Browse Topic: Frames

Items (1,482)

Analytical Analysis of Wellbore Stresses under Fluid Pressure and In-Situ Stress in Three-Dimensional Wellbores

2026-99-0831

7/30/2026

During fluid injection operations such as fracturing and well killing, the casing, cement sheath, and borehole wall rock are subjected to three-dimensional in-situ stresses and internal pressure. If the equivalent stress exceeds the material’s yield strength, component failure may occur, leading to wellbore failure or even blowout accidents. In order to investigate the stress distribution in wellbores under specific working conditions, a three-dimensional mechanical model of curved wellbores was established. By adopting the superposition principle and stress function method, the influence of horizontal in-situ stress non-uniformity on the fourth equivalent stress of various components was analyzed. The study demonstrates that under three-dimensional in-situ stress, the fourth equivalent stress of each component increases with the rise of horizontal in-situ stress load non-uniformity and azimuth angle. Meanwhile, borehole azimuth angle and in-situ stress load non-uniformity exert a greater influence on the fourth equivalent stress of the casing, while internal pressure has a lesser impact on it. The effects of azimuth angle, horizontal in-situ stress load non-uniformity, and internal pressure on the fourth equivalent stress of the casing are more significant than those on the cement sheath and borehole wall rock. The research results can provide theoretical and technical references for wellbore design and safety improvement, as well as for the structural safety assessment of components such as automotive chassis and body frames under complex dynamic loads.

Zhang, Wenzhe, Jiang, Wu, Guo, Ziwang, Cao, Yinping, Dou, Yihua

Adaptive Attitude Adjustment Mountain Transport Vehicle for Electric Tower Material

2026-99-0850

7/30/2026

Transporting large steel materials for mountain electric towers is challenging due to steep gradients, narrow roadways, and uneven terrain. To address these issues, this study designs an adaptive attitude adjustment mountain transport vehicle. This mountain transport vehicle has a compact structure, measuring 1.4 meters in length and 1.1 meters in width, which enhances its suitability for confined mountainous environments. This vehicle adopts a design scheme that combines hydraulic lateral adjustment, load-bearing platform follow-up adjustment and frame adaptive adjustment mechanisms. The transportation of tower materials, measuring 12 meters in length and 1.2 tons in weight, is accomplished by employing two vehicles working in coordination. The three-dimensional model of the entire vehicle is established by using SolidWorks software. The lateral stability of the mountain vehicle and the limit working conditions of its adjustment mechanism are analyzed through theoretical calculation. The dynamic simulation of the virtual prototype is carried out using Adams software, including the processes of lateral leveling, follow-up adjustment and frame adjustment. The results show that the leveling mechanism can achieve an adjustment range of more than ±25°. The results confirm the vehicle’s excellent stability and adaptability to mountainous conditions. This study provides a more effective and more reliable solution for the construction of mountain electric towers than traditional manual or animal-powered transportation methods.

Zhang, Rui, Kong, Fanfang, He, Yuling, Lv, Jiahui, Chen, Changlong, Zhan, Lulin, Liang, Ke

Lightweight Optimization Design of Subframe Structure Based on Sensitivity Analysis

2026-99-1639

7/24/2026

In order to meet the needs of national energy conservation and environmental protection policies, a typical chassis structure lightweight method based on sensitivity analysis of 13 strength conditions was proposed. Firstly, the finite element model of the subframe of a certain model is established, and the impact strength and static strength of the subframe structure are analyzed by the finite element method. Secondly, the sensitivity analysis of 13 strength conditions was carried out for the 12 main sheet thicknesses in the finite element model. Based on the results of the sensitivity analysis, the plate thickness of the components that is conducive to lightweight and has little impact on the 13 strength conditions of the subframe was selected as the design variable. The size optimization was carried out with the goal of minimizing the mass of the subframe and the constraint that the maximum Von Mises stress of the unit, where each material is located, did not exceed the yield strength of the material. The optimization results show that the performance of the subframe under 13 strength conditions meets the requirements of the index, and the weight of the subframe is reduced by 1.37 kg / 9.6%.

Jing, Min, Jia, Zhilong, Zhang, Hualei, Liu, Minjie, Gan, Xinhua, Gao, Jinyu

Multi-Frame Centroid Extraction Method for Optical Navigation During the Approach Phase of Small Body

2026-99-1851

7/17/2026

Autonomous optical navigation is one of the important navigation methods for the small bodies approach phase. To improve optical navigation performance during the approach phase to a small body, this paper presents a method for extracting the target centroid from sequential optical images. The process begins with fitting a minimum enclosing ellipse to the detected contours in each frame to obtain an initial estimate of the centroid. Building upon this, edge corner points across adjacent images are matched using normalized cross-correlation, and their displacement is tracked using optical flow techniques. The observed pixel trajectories are analyzed, and a predictive model of pixel motion is formulated based on the geometric relationship between the detector and the small body. By combining the directly extracted centroids with the predicted motion of key pixels, a fusion strategy is developed to improve the reliability of the centroid estimation. Finally, numerical simulation results demonstrate that the method significantly improves the accuracy of centroid extraction, thereby enhancing the overall performance of optical navigation during approach operations.

Liu, Jing, Zhu, Shengying

Experimental Validation of Frame-Dependent Gyroscopic Frequency Splitting in a Freely Rotating Tire Using Wireless MEMS Accelerometers and Scanning Laser Doppler Vibrometer

2026-01-0700

6/20/2026

Gyroscopic effects split circumferential traveling-wave resonances of rotating structures into forward and backward branches. This work first analyzes the splitting in the co-rotating (Lagrangian) frame to provide physical intuition for the evolution of the two branches with spin speed. A transformation to the inertial (Eulerian) frame is then derived, showing that the observed frequencies are shifted by a kinematic Doppler-like term that acts with opposite sign on the forward and backward waves, leading to different Campbell-diagram slopes depending on the observation frame. The resulting framework is validated experimentally on a freely rotating, unloaded tire using two complementary sensing modalities: wireless on-tire accelerometers (co-rotating view) and a scanning laser Doppler vibrometer (inertial view). A frequency-domain SVD-based identification (FDD/ODS-SVD) is used to extract poles and deformation patterns over a range of spin speeds, enabling Campbell diagrams in both frames. The application of the proposed transformation maps the co-rotating branches onto the inertial observations, yielding consistent forward/backward splitting between the two measurement systems.

del Fresno Zarza, Javier, Naets, Frank

Hierarchical Control Strategy Evaluation and Migration for a Four-Degree-of-Freedom Quarter Commercial Vehicle

02-19-03-0014

4/9/2026

In order to improve the comfort performance in commercial vehicles, this study proposes a hierarchical control strategy that integrates the evaluation and migration of control algorithms. First, a quarter-vehicle model with four-degree-of-freedom (4-DOF) is constructed, incorporating the dynamics of the wheel, frame, driver’s cab, and seat. The key modal characteristics of the model are then verified through amplitude–frequency analysis, confirming their consistency with the typical vibration patterns observed in actual commercial vehicles, which provides the foundation for subsequent control strategy evaluation and migration. Then, based on a standard two-degree-of-freedom (2-DOF) suspension model, a weighted comprehensive evaluation function is developed to account for comfort, structural safety, handling stability, and both time- and frequency-domain performance indicators. Using this evaluation function, various control algorithms—including Skyhook control (SH), acceleration-based damping control (ADD), and proportional–integral–derivative control (PID)—are systematically assessed. The control algorithm is migrated to the 4-DOF model to carry out the hierarchical collaborative control. The results show that this method can effectively inhibit vibration transmission to enhance ride comfort and improve structural safety at the same time, while maintaining an acceptable level of handling performance. The transferability and applicability of the hierarchical control method are validated for the considered vertical dynamics scenarios. This article provides a new theoretical method and technical pathway for the comfort-oriented performance optimization of commercial vehicles.

Pan, Ting, Pang, Jianzhong, Wu, Jinglai, Zhang, Jiuxiang, Kang, Gong, Zhang, Yunqing

Ultra-Low Latency Video Pipeline Optimization for Perception-Centric Autonomous Systems

2026-01-0022

4/7/2026

Autonomous platforms such as self-driving vehicles, advanced driver-assistance systems (ADAS), and intelligent aerial drones demand real-time video perception systems capable of delivering actionable visual information at ultra-low latency. High-resolution vision pipelines are often hindered by delays introduced at multiple stages—sensor acquisition, video encoding, data transmission, decoding, and display—undermining the responsiveness required for safety-critical decision making. This study introduces a holistic system-level optimization framework that systematically reduces end-to-end video latency while maintaining image fidelity and perception accuracy. The proposed approach integrates hardware-accelerated encoding, zero-copy direct memory access (DMA), lightweight UDP-based RTP transport, and GPU-accelerated decoding into a unified pipeline. By minimizing redundant memory copies and software bottlenecks, the system achieves seamless data flow across hardware and software boundaries. Evaluations demonstrate a latency reduction from a baseline of 45.3 milliseconds to an optimized 23.5 milliseconds, representing a 48.1% improvement without sacrificing spatial resolution or detection robustness. Under optimized configurations, the framework sustains frame rates above 60 FPS at both Full HD and 4K resolutions, with frame drop rates held to approximately 3%. Perceptual evaluation further confirms that object detection accuracy consistently exceeds 91% within the <35 ms latency range, while collision-prediction delays are reduced to below 12.4 ms, ensuring timely responses in dynamic scenarios. These improvements collectively validate the critical importance of hardware-software co-design for embedded vision systems. The results highlight that ultra-low-latency perception is achievable on edge platforms when pipelines are designed with cross-layer optimization, bridging sensor interfaces, video codecs, network transport, and GPU computation. The proposed architecture provides a scalable foundation for future embedded vision deployments in autonomous driving, robotics, and unmanned aerial systems, where low latency is a non-negotiable requirement for safety, reliability, and operational efficiency.

Indrakanti, Rama Kiran Kumar

OFEODM: An Vehicle Onboard Fast and Efficient Object Detection and Distance Prediction Model

2026-01-0017

4/7/2026

Object detection and distance prediction have advanced significantly in recent years. The YOLO toolbox has released its 11th version, along with numerous variants that have been applied across various fields. Meanwhile, the Detection Transformer (DETRs) has repeatedly set new state-of-the-art (SOTA) records in the field of object detection. Depth Anything also released its second version last year, further pushing the boundaries of distance detection. Although these models achieve impressive performance, they often require substantial computational resources. However, for the algorithms intended for real-world applications and deployment on onboard devices, computational efficiency are extremely critical. Inference time per frame is a critical factor in ensuring an algorithm’s reliability and feasibility. Designing a model that operates in real time without sacrificing accuracy remains an extremely challenging problem, and extensive research is ongoing in this area. To address this challenge, we present a model called the Fast Detection model, which runs in real time on a comma 3X device equipped with a Qualcomm Snapdragon 845 processor. We deployed the comma 3X device on a 2025 Nissan Leaf electric vehicle for autonomous driving purposes. Furthermore, experimental results of comparing our model to the state-of-the-art one-stage object detection models of the YOLO series indicate that our model demonstrates comparable performance but with faster speed on our collected real-world dataset. Additionally, we have incorporated an extra module into our Fast Detection model that enables it to predict the distance between our vehicle and detected objects, providing valuable information for downstream tasks such as path planning.

Li, Taozhe, Wang, Hanchen, Hajnorouzali, Yasaman, Xu, Bin

ProGuard: A Real-Time Preemptive Artificial Intelligence-Based Anti-Pinch System for Bus Entryways on Low-Power Edge Devices

2026-01-0100

4/7/2026

This paper proposes ProGuard, a novel approach to preemptive pinch detection systems for buses. ProGuard utilizes state-of-the-art AI object detection algorithms to identify potential pinching events in bus entryways before pinching occurs. Modern conventional anti-pinch systems, such as pressure sensors or hall effect sensors, often rely on mechanical contact before triggering. While these systems are established safety mechanisms, they are reactive and therefore require some level of pinching before triggering. This reactive approach presents numerous safety concerns for passengers, especially when considering children on school buses. Existing preemptive detection methods, such as infrared or ultrasonic sensors, solve the problems presented by these reactive detection systems. However, these systems either lack the range or environmental resilience needed for reliable operation in buses. The critical nature of anti-pinch systems requires a robust and reliable solution that can adapt to various applications and environments. Our study investigates an AI-based approach that leverages the YOLOv11 nano object detection model to detect people and backpacks in real-time. We performed a comparative study on various model formats to find the best-performing format on the chosen edge compute hardware. Our experimental results revealed that when using the IMX model format on an AI-accelerated camera, ProGuard can achieve 24 frames per second and an inference time of 125ms while running on a Raspberry Pi computer. Performance tests on this model showed a mAP@0.5-0.95 of 0.522, putting ProGuard on par with baseline YOLOv11 nano performance. These results demonstrate that ProGuard offers an efficient and real-time alternative to current pinch detection approaches while operating on low-cost consumer hardware.

Bradley, Hudson, Zadeh, Mehrdad, Tan, Teik-Khoon

Acoustic Improvements to a Passenger Service Unit Panel with Core Filler and Facesheet Patches using Topology Optimization

2026-01-0511

4/7/2026

Passenger comfort is becoming the forefront of luxury private jets where noise needs to be kept to a minimum. One source of structure-borne noise is the vibration of the Passenger Service Unit (PSU) panel. These vibrations originate from the outer skin, excited by turbulent boundary layer, and are transmitted through the fuselage frame to the PSU panel. This panel resides overhead of passenger seating, it is composed of a corrugated honeycomb core sandwiched between thin face-sheets. This paper presents a systematic approach to improve the vibro-acoustic performance of a honeycomb core sandwich structure by employing core filler and facesheet patches. Topology Optimization (TO) is used to determine the optimal layouts of these design modifications. The vibro-acoustic performance of the PSU panel with facesheet patches and core filler is evaluated using a frequency response analysis in the commercial finite element solver OptiStruct. The effectiveness of vibration reduction will be quantified by using the Dynamic Stiffness (DS) and velocity response of the PSU panel measured using the Frequency Response Function (FRF). Validation used excitations from 500 to 3000 Hz and indicated that using the TO interpreted layout of core filler and facesheet patches, separately improved the DS of the panel by 402% and 198%, and the velocity response by -35% and -18%, while increasing the weight by 0.1% and 4.7% respectively. Their combined effect has also been tested and found to provide an additional 445% improvement to DS and a -39% improvement in velocity response with 4.8% of additional material, though overall behavior varies depending on frequency range.

Russo, Connor, Whetstone, Isobel, Patel, Anuj, Wotten, Erik, Kim, Il Yong

HaloBus: Edge Computing-Enabled Real-Time Boarding and Exit Detection for Enhanced Transportation Safety Using Lightweight AI

2026-01-0555

4/7/2026

This paper proposes HaloBus, an innovative, edge-computing solution designed to mitigate this risk by detecting student boarding and exiting in real time using lightweight AI based methods. A persistent challenge in elementary school transportation is the issue of missing students after they exit their buses, which disproportionately impacts low-income households. Current safety systems place the burden of implementation on individual households, often requiring independent methods. Common methods include applications on a personal device or a small tracker. However, not everyone can afford these options, and ensuring child safety is a primary concern for parents and caregivers. That is why HaloBus was invented. The system employs YOLOv5us—an Ultralytics-enhanced, anchor-free, split-head architecture that offers a superior accuracy speed trade-off. By providing real-time, on-device alerts, HaloBus enables immediate intervention to prevent a student from being left behind, thereby shifting the focus from reactive post-incident response to proactive safety. Trained on over 70,000 labeled and unlabeled images, the model can accurately detect multiple students simultaneously, significantly reducing false positives. In real-world deployment, the model sustained 30 frames per second on the Raspberry Pi and achieved detection confidence levels exceeding 75% even when subjects wore sunglasses or hoodies. With opt-in participation for each family, HaloBus effectively balances detection efficiency and privacy protection. Overall, HaloBus offers a low-cost, scalable, and ethically conscious approach to enhancing school-bus safety by delivering reliable, on-device boarding and exit detection for multiple students in varied real-world conditions.

Getz, Grayson, Zadeh, Mehrdad, Tan, Teik-Khoon

Design, Fabrication, and Assessment of a User-Friendly Suspension System for a 2025 BAJA Vehicle

2026-01-0588

4/7/2026

A suspension system was designed, fabricated, and tested following a systems design approach by an SAE Off-road Team from a North Midwest university. Compared to previous suspensions, the new suspension system is more reparable and contains a minimal number of custom parts, while still maintaining sufficient strength to withstand dynamic loads experienced when operating the vehicle. Modifications were also made to fit the newly designed vehicle body frame. As an integral part of the team’s 2025 Baja vehicle, the redesigned suspension system contributed to the vehicle’s improved performance during the 2025 SAE (Society of Automotive Engineers) Baja Competition. This paper presents a detailed account of the design, development, and fabrication process of the suspension system. The final design was tested and evaluated via both computer simulations and physical tests, whose efficiency and reliability were finally demonstrated by the team’s improved ranking in the 2025 Baja SAE Competition.

Liu, Yucheng, Anderson, Matthew, Larson, Cody, Rodgers, Joshua, Seberger, Aaron, Letcher, Todd

Design and Simulation Analysis of an Integrated Honeycomb-Filled Front Bumper for a Special Vehicle

2026-01-0475

4/7/2026

In frontal collisions of automobiles, the bumper beam at the front of the vehicle plays a crucial role in absorbing energy and protecting the vehicle body during a collision. To enhance the collision resistance of a specific type of special vehicle with a non-load-bearing body structure, this paper focuses on this type of vehicle and conducts a study on the design and collision performance of an integrated vehicle front bumper - anti-collision beam structure based on aluminum alloy additive manufacturing technology. A novel bumper structure is proposed, which integrates the front bumper and the front anti-collision beam of the vehicle and is integrally formed using aluminum alloy additive manufacturing technology. This integrated structure is directly connected to the vehicle frame. Firstly, based on the appearance of the special vehicle body and the form of the front anti-collision beam of traditional passenger vehicles, an integrated design of the vehicle front bumper- anti-collision beam structure is carried out and connected to the vehicle body. Subsequently, based on the previous bumper design, a honeycomb structure is introduced internally, and the introduced honeycomb structure is integrally formed with the front bumper. Finally, finite element simulation analysis of two types of frontal bumper collisions under the same collision conditions is conducted. The results show that the initial integrated front bumper can achieve basic anti-collision beam functions, while the front bumper with a honeycomb composite structure can improve the transmission path of collision force, ensure stable deformation, significantly enhance the energy absorbed during a collision, and increase the specific energy absorption, indicating that the integrated honeycomb-filled front bumper can effectively enhance the collision resistance of special vehicles.

王, Xufan, Yuan, Liu-Kai, Zhang, Tangyun, Wang, Tao, Zhang, Ming, Wang, Liangmo

Determining Video Frame Capture Rate through Reverse Engineering

2026-01-0543

4/7/2026

The timing of video recordings, along with the spatial positioning of objects, is a fundamental parameter for calculating the speed time history. If the task involves determining the average speed of an object moving at approximately constant speed, it may be acceptable to average the speed over several to a dozen frames, using the fps (frames per second) parameter as the basic time unit.. However, if the objective is to compute speed from individual frames, the reliability of the timing becomes crucial. Without access to DVR hardware documentation, proprietary algorithms, or software – and considering the frequent hardware modifications and software updates - the most effective way to solve the problem is through a reverse-engineering approach. This study discusses several aspects of timing analysis, including: (1) making a test recording of a calibrated LED lightboard; (2) analyzing the relationship between the lightboard time and the presentation time stamp (pts) extracted from the file metadata; (3) investigating frame skipping and frame timing errors due to frame rate changes; (4) modeling the composite motion of the rolling shutter and the lightboard LEDs; (5) identifying the DVR’s actual frame capture rate; and (6) compensating the timing of the evidentiary recording. Establishing the timing scheme of the test recording enables reliable speed analysis based on two or three adjacent frames of the evidentiary recording, as well as the determination of the velocity time history over a short segment of the recording.

Wach, Wojciech

Failure Cause Analysis of Valve-Regulated Lead-Acid Battery on Fire in Communication Equipment Room

2026-01-7022

2/27/2026

This paper carried out the fire failure analysis of valve-regulated lead-acid battery in communication equipment room. Through disassembly and observation of the battery and iron frame of battery cabinet in the area of fire origin, we obtained the key residual traces and used the physical and chemical analysis methods such as macroscopic/microscopic morphology, EDS, X-ray and metallographic, it was finally judged that the leakage of the battery electrolyte lead to the connection of the battery electrode plate and the iron frame and subsequently the electric heating fault caused the fire accident. Furthermore, we put forward some suggestions according to the existing problems, which may contribute to the prevention of similar failures.

Guo, Yuhang

Design evolution of Novel Subframe for a Multilink Rear Suspension of an e-SUV

2026-28-0007

2/12/2026

As there is a major shift in customer demand for energy efficient transportation, electric vehicle development has taken prominence worldwide as they provide pollution free and noise free mobility. The subframe being an important structural component of the chassis system, the designers always find it challenging to provide best-in-class rear subframe (RSF) optimized in terms of cost and weight within the available packaging space especially in an electric sport vehicular boundary. The main function of rear subframe is to transmit forces to BIW without deflections hence for this it should be very stiff. At the same time, it should be light in weight and simpler to industrialize. In the present work, the design evolution of a novel sub-frame assembly for a multilink rear suspension of a born electric sports utility vehicle (e-SUV) platform is detailed. With increased rear axle weight contributed by the battery weight and rear mounted motor, the design evolution of the rear subframe (RSF) to overcome the inherent challenges is elaborated. The present RSF assembly consists of a uniquely designed cross member structure and a novel motor mounting concept on the long member for the complexity in the finalized hard points for the suspension linkages, to meet the electric vehicle packaging requirement. The RSF was designed for light weighting to withstand the increased stresses due to 20% higher vehicle weight of the e-SUV compared to the conventional internal combustion engine (ICE) vehicle. Furthermore, the weight of the RSF was optimized by using a lower sheet metal panel thickness of 1.6mm with conventional sheet metal material grade to reduce the cost and weight by 10% without compromising the durability and NVH targets. Strategic arrangements of reinforcements and novel construction aided the RSF to overcome the handicap of increased stresses and reduced weight. Thus, the design evolution of the novel RSF assembly is detailed in the present work.

Nidasosi, Basavraj Maruti, J, Ramkumar, Nayak, Bhargav, Mani, Arun, M, Sudhan

Comprehnsive Measurement and Evidential Evaluation of Driver Drowsiness and Alertness Warning System

2026-26-0520

1/16/2026

The paper aimed to improve the accurate quantification of driver drowsiness and to provide comprehensive, evidence-based validation for a Vision-Based Driver Drowsiness and Alertness Warning System. Advanced quantification of driver drowsiness is designed to enhance distinction of true positive events from False Positive and False Negative events. Methodology to pursue this included assessing inputs such as facial features, driver visibility, dynamic driving tasks, driving patterns, driving course time and vehicle speed. The system is programmed to actively learn Eye Aspect Ratio (EAR) reference and adapt personalised EAR threshold value to process EAR frames against the learnt threshold value. This method optimized the data frames to enhance the evaluation and processing of essential frames, thereby reducing delays in the processor and the Human-Machine Interface (HMI) warning module. Comprehensive validation is systematically conducted within a controlled test track environment to ensure precise execution of protocols, maintaining inputs closely aligned with real-time scenarios. The test methodology comprised the execution of pre-defined protocols that is steering robot and a technology-neutral procedure. Pre-defined protocols are scenarios created using the aforementioned assessing inputs. Cartesian coordinates of the system’s camera and driver eye point relative to the seating reference point (SgRP) are identified using a coordinate measurement machine (CMM) to measure the driver's position within the camera's field of view and mark the visibility zones. The protocols are executed with precision using a global navigation satellite system (GNSS), visual sensor, audio sensor and data logger. Subsequently, the system is tested with number of drivers trained on the Karolinska Sleepiness Scale (KSS) to conduct technology-neutral method for statistical analysis. Detailed analysis of the tested data, concluded with results and explored future prospects for quantifying driver drowsiness are discussed. The paper also discussed observations and challenges associated with the functionality of conventional systems and protocols currently deployed in the market.

Balasubrahmanyan, Chappagadda, Akbar Badusha, A

Experimental Evaluation of Metro Rail Bogie Frame through Bench Testing

2026-26-0561

1/16/2026

Bogie frame is a main skeleton and structural member in railway system which is carrying all the loads such as Suspensions, Axles, wheels, car body, Motor, Gear box etc. The frame is subjected an exceptional and service stresses in Vertical, Longitudinal, Lateral and twist directions throughout the service life which should be withstand for a life span of 30 years without failure. The purpose of this project is to determine the Structural integrity of the Metro rail bogie frame in consideration with EN13749 standard. This paper is the outcome of bench testing of metro rail bogie frame with the application of multiaxial loading in static and dynamic campaign through which stress data is collected with strain gauge sensors and correlated with the FEA results at initial design phase. This helps to verify and evaluate the design and validate the quality of metro rail frame as per the requirement specified in EN13749:2021 European standard in early design stages.

Tormal, Uday Bapurao, Sinnarkar, Nitin, Shinde, Vikram

Methodology for Optimizing the Bench Testing of Steering I-Shaft Using Vehicle Level Data to Reduce Overall Product Development Time and Cost

2026-26-0560

1/16/2026

Steering I-shaft with rubber coupling (or hardy disc) is an important part of complete steering system mainly in body on frame (BOF) vehicles. Hardy discs are used to dampen the vibrations that transmit to steering wheel through frame, steering gear and I-shaft. They also support to accommodate the variation between frame and BIW (Body in white) of body on frame vehicles. They are made up of rubber or other polymer composites, which have less torsional stiffness as compared to metals. The overall torsional stiffness of steering system reduces since the hardy disc is used in series in steering system, that impacts on the overall performance of steering system. So, during development of I shafts with different design, stiffness of hardy discs are used to optimize the steering and NVH performance of vehicle. Considering the development time and cost, each design of I-shaft cannot be validated at vehicle level. The torsional and axial force or displacement of hardy disc is measured at vehicle level on different test tracks and block cycles are made that consists of different displacement / force along with frequencies. These block cycles are then used at bench level testing of I-shafts. This paper summarizes the methodologies to measure the force or displacement of I- shaft, converting raw data to useful block cycles and test set up for bench testing of steering I-shaft.

Kabdal, Amit

Packaging the HPTS Airbag in a Second-Row Seat

2026-26-0033

1/16/2026

Seats of modern cars should necessarily meet the regulatory safety norms along with aesthetics and comfort. In the existing passenger cars prevailing across the Indian subcontinent, the measure of safety has been a challenging one. The stringent regulatory norms thereby make the Airbag very promising. In the Automotive industry, safety features are very important, one of the topmost features which falls in this category is airbags. The driver and passenger safety during high impact collisions and sudden crashes is the key objective of airbag. This safety is provided by the airbag with its automatic deployment. The inflatable airbag is engineering in a way to respond very quickly during a collision and furnish necessary cushioning to decrease the impulse and enhance the safety of the passenger. The technology has been practiced widely upon many vehicles' seats. However, the present work highlights a novel approach of packaging the HPTS air bag in second row seat. This Air bag unit is fitted in the seat back frame at outboard ends of backrest. The modification is done in seat frame, foam, and trim in such a way to Airbags should be deployed in moderate to severe collisions. This study revolves around the integration and modifications in the mandatory HPTS airbag packaging requirements. This study is done to emphasize the engineering and regulatory prerequisites and their respective challenges. This study also touches on the details of mounting schemes and the evaluation of the perceived quality in implementing HPTS airbag feature on the second-row bench seat.

Buradkar, Rajat, Bose, Karthik, Jadhav, Deepika, Balakrishnan, Gangadharan

Effect of Pipe Bending by Rotary Tube Bending Process on Durability of Frame Structure

2026-26-0370

1/16/2026

Automobile frames, particularly trellis frame structures, are engineered for superior dynamic performance, with stiffness being a paramount consideration1. These frames frequently utilize welded tubes, a manufacturing process made more complex by the necessity of bending tubes to precise angles to meet packaging and assembly requirements2. This bending, however, induces residual stresses that can substantially compromise the frame's durability3. This investigation employs a detailed finite element simulation to analyse the structural deformation and residual stresses that arise during the bending of Cold Electric Welded (CEW) annealed round pipes4. A comprehensive 3D mechanical model, incorporating realistic tooling and contact interactions, was developed to accurately simulate shape change, ovality, and wall thickness redistribution during the bending process5. CEW pipes, unlike their Electric Resistance Welded (ERW) counterparts, possess minimal initial forming stresses, and the annealing process ensures they are stress-free prior to bending, facilitating a more controlled analysis of their deformation6. The simulation results reveal significant geometric alterations in the bent region, including changes in ovality and wall thickness, which are heavily influenced by the bend radius and angle7. The residual stress analysis indicates a combination of tensile and compressive stresses that could jeopardize the pipe's structural integrity8. Furthermore, deformation in the bend zone can lead to welding issues such as uneven fit-up, altered section modulus, and irregular weld profiles, all of which can diminish weld joint performance9. To address these challenges, a conservative approach was adopted in our fatigue analysis using FE-Safe, applying the lower bound of weld material properties to account for potential weld imperfections stemming from bending10. These simulation outcomes are critical for evaluating the fatigue life of weld joints and comprehending how bending affects the pipe's long-term performance11. Ultimately, this research aims to enhance the reliability and efficiency of piping systems, especially in trellis structures, by improving the accuracy of fatigue simulations12. The insights gleaned will aid in optimizing bending processes, refining weld joint designs, and supporting the development of robust tubular structures for demanding applications13.

Rajwani, Ishwar, Khare, Saharash

3D Multi-Object Tracking Based on Probability Distribution and State Regression

2025-01-7314

12/31/2025

In previous multi-object tracking paradigms, a complex data association strategy is generally needed to achieve accurate matching for detections and trajectories. In this paper, a novel end-to-end 3D multi-object tracking (MOT) framework is proposed based on probability distribution and state regression. Firstly, this framework does not rely on complex data association strategies; instead, it derives the accurate position of an object in the current frame directly by regression based on the prior information of the object’s trajectory. Secondly, a probability grid sampling strategy is then adopted to expand the regression search range of the trajectory in an adaptive manner, thereby reducing the uncertainty of the trajectory states caused by consecutive predictions. Lastly, to eliminate overlaps of trajectories, a trajectory interaction module is introduced to retain trajectories with higher confidence. Experiments are conducted on the KITTI and Waymo datasets. The results demonstrate that this framework can achieve robust tracking by utilizing only a single 3D detector, outperforming many tracking-by-detection methods.

Liang, Zheng, He, Jiawei, Ji, Pan, Huang, Mingguang, Cheng, Hao, Fu, Chunyun

LLS-SMGSC: A Lidar Localization System Based on Simplified Maps Integrated with Global Search Capabilities

2025-01-7303

12/31/2025

To address the issues of large storage requirements in maps and the dependence of localization accuracy on initial pose estimation, this paper proposes a novel relocalization method named LLS-SMGSC, which is based on simplified maps integrated with Global Search capabilities. Firstly, we partition the map-based on grid size to reduce memory usage. Next, we voxelize the point cloud and map and extract surfel. Then, a coarse-to-fine hierarchical alignment module between the initial frame and maps to estimate the initial global pose. Finally, unmanned platform pose is estimated by the Normal Distribution Transform (ndt) algorithm. Experiments demonstrate that LLS-SMGSC achieves the highest localization accuracy in both unstructured and structured environments while maintaining computational efficiency.

Quan, Zhiheng

Analysis of the Structural Alignment during the System Conversion of Continuous Beam Bridges with High Piers, Long Spans and Wide Box Girders

2025-99-0224

12/23/2025

With the rapid development of the worldwide highway transportation industry, continuous box girder bridges have many advantages, such as superior spanning capacity, reasonable force-bearing performance, and low cost, which give them significant strengths in bridge design. However, to ensure that the structural alignment of the girder meets the design and specification requirements, it is necessary to study the laws of alignment changes of cantilever structures during the construction process. This is to reasonably control the alignment of the main girder structure during construction and ensure that the alignment of the completed bridge is consistent with the design alignment. This paper takes a continuous rigid frame bridge on a certain expressway as the engineering basis. Its superstructure is a three-span prestressed concrete continuous box girder with a span of (88 + 160 + 88) m, a bridge width of 16.5 m, and a maximum pier height of 130 m. The paper analyzes the influence of each construction stage on structural deformation during the system conversion construction process of the structural girder. A structural model is established using Midas/Civil, and the laws of structural deformation during the system conversion process as well as the differences in the peak values of structural deformation under different closure sequences are analyzed and summarized. The calculation results show that during the system conversion process of the girder, the structural alignment undergoes different changes, and different closure sequences also have an impact on the peak values of structural deformation. This indicates that it is necessary to monitor the alignment of the girder during construction and determine a reasonable closure sequence, which can provide a reference for the construction procedures and construction monitoring of similar structures under similar conditions.

Liu, Xingshun, Ma, Kun, Zhao, Qiang

Optimization Design of Typical Vehicle Frame Structure Using Power Flow Transmissibility Objective Function Method — Taking SD160-3 Model as an Example

2025-99-0213

12/23/2025

According to a problem of the vibration and noise suppression of an engineering vehicle cab, a dynamical model of the engine-frame-cab system was established to describe the vibration transmission path. The method of calculation of the vibratory power flow, which is transmitted from the vibration source engine to the cab through the frame and isolators, was deduced. And then an optimization strategy for the frame structure and the corresponding analysis algorithm process were proposed based on the objective function of power flow. The method proposed was validated through an application to a practical example, which would have practical value in the field of vehicle vibration reductions and optimization design of frame structures.

Wang, Qiang, Huo, Rui, Guan, Yanfeng, Zhang, Daokun

Lightweight Design and Optimization of Multi-Terrain Multi-Functional Tracked Amphibious Vehicle

2025-99-0324

12/17/2025

In view of the complex intertidal terrain challenges faced by offshore wind power maintenance, this paper optimizes the lightweight design of multi-terrain tracked vehicles. The structure was optimized by finite element analysis, and the maximum stress was 211.68 MPa ( lower than the safety limit of 230 MPa), and the maximum deformation was 5.25 mm, which ensured the stability and stiffness. Titanium alloy has the advantages of high strength, low density and corrosion resistance, which improves the durability of the frame while reducing the weight of the frame. Advanced manufacturing technologies such as phase transformation superplastic diffusion welding optimize the connection between TC4 titanium alloy and stainless steel. Modal analysis and optimization techniques refine the structural parameters and improve the complex load performance. The research promotes the lightweight of the frame and provides theoretical and technical support for the design of multi-terrain vehicles.

Xu, Han, Xu, Shilin, Ma, Wenbo, Zhu, Wei

Shock Dynamics Analysis of Opening Process of Spring Mechanism for Circuit Breaker

2025-99-0354

12/17/2025

In order to accurately evaluate the strength and stiffness of the key components of the spring mechanism for circuit breakers under strong impact load conditions, and provide strong data support for product design and structural optimization, the impact dynamics analysis method is used to model and simulate the spring mechanism. The dynamic stress test data is used to verify the accuracy of the simulation, and the strength of the key components under impact conditions is obtained. The influence of different stiffness frames on the output shaft offset is analyzed.

Guo, Mingqin, Li, Junfeng, Yin, Tianshuo, Zhang, Pan, Li, Pengzhen, Wang, Pengchao, Ji, Linhao

The Simulation Study of Support Schemes for Transition Zones in Double-Fault Tunnels

2025-99-0443

12/10/2025

When a tunnel passes through the transition zone between two faults, different support schemes have varying impacts on the deformation of the surrounding rock. This study, based on the Zhangzhuang Tunnel's double-fault area, establishes a numerical simulation model using Midas GTS NX to compare and analyze the effects of an enhanced support scheme versus a standard reinforcement scheme. The results indicate that when the non-reinforced support scheme is applied throughout the tunnel, the settlement of the transition zone's crown is 5.7 mm, only 0.27 mm greater than that of the reinforced scheme. Additionally, the variation in support stress in the transition zone between the two schemes is minimal. This demonstrates the feasibility of adopting the non-reinforced scheme, which reduces the number of steel arch frames, enhances construction efficiency, and provides a reference for future construction of small-section tunnels in double-fault conditions.

Wu, Jianmin, Niu, Shuo, Zhang, Te, Meng, Xianghua

Digital Simulation of Rear Axle Brake Lines Articulation for Commercial Vehicles

2025-28-0257

11/6/2025

This paper focuses on defining the optimal length of rear axle brake lines (flexible polyamide tubes) for commercial vehicles by simulating the lines digitally by considering tube behavior and various axle articulation conditions. Currently, the length of rear axle brake lines are predominantly defined with the help of a physical mockup by articulating axle conditions in a vehicle. This approach requires actual components such as frame, axle, suspension, etc., which consumes considerable time and cost. Through technological advancements, prototyping can be reduced and convergence on digital to build can be achieved through digital simulation. This paper explores tube properties, axle configurations and definitions, and various methods of digitally simulating line articulation. Boundary conditions, space reservations and design criteria for pneumatic routing are defined for the type of line designed. Digital simulation of rear axle brake lines articulation was performed and compared with prototype. The experimented method of digitally simulating line articulation significantly reduced the design iterations. And as a case study, the findings are discussed in detail.

Duraiswamy, Rupesh, Sankaran, Bhargav, Raj, Santhosh

Analysis of a Battery Bicycle with a Sliding Mechanism for Need-Based Adjustments for Luggage Space

2025-28-0405

10/30/2025

A battery bicycle with luggage space is designed and developed to have variable luggage space available to the rider. The developed design with bicycle frame has an innovative sideway moving frame for variable need-based space. The design was prepared for an e-commerce delivery application, suppling products through an easy, quick, and low-cost mode of transport with variable spacing options. The design was prepared for 160 kg weight, with 210 cm, 90 cm, and 35 cm as length height and width, respectively. The designed bicycle can carry luggage up to 100 kg. The design is powered by a 250-watt electric motor and can move with a maximum speed of 24 km/hr. The steering mechanism, cargo bucket, and the base frame are made in two parts for commuter convenience. The cargo bucket is front-mounted, on a sliding frame that enables one half of the bucket to be slid into the other half through sideways movement by fitted channels. The design has both electric and non-electric driving modes. The design finds application for delivering goods, personal applications, and some industrial work. The electric-driven feature helps in climbing elevated terrain and reduces fatigue during the load-carrying applications. Testing of the designed bike is made with the application of different resistances that include rolling, wind, and gradient resistances. Test results suggest that the developed bicycle helps users fulfill their transport requirements of movement of their product better, compared to the already existing product.:

Vashist, Devendra, Satti, Harsh, Awasthi, A.K, MUKHERJEE, SOURAV

Analysis of Time-Sensitive Networks for Mission-Critical Systems

2025-01-0464

9/16/2025

Time-Sensitive Networking (TSN) enhances Ethernet with features such as time synchronization, scheduled traffic, policing, and redundancy to enable highly deterministic and reliable communications in mission-critical systems. This paper presents a comprehensive approach to the configuration, analysis, and verification of TSN for critical systems, with a focus on time-sensitive applications such as tank barrel stabilization. The impact of different types of topologies, traffic types, and application requirements on the configuration complexity are presented along with various mathematical techniques to generate network solutions and verify against the system requirements. Detailed modeling, configuration, and analysis of TSN is demonstrated using a representative mixed criticality converged network. Lastly, configuration techniques to minimize the latency, jitter, and frame loss while maximizing the network utilization are presented.

Bush, Stephen F., Jabbar, Abdul

Design and Analysis of Passive Controlled Plastic Hinge in Two-Post Rollover Protective Structure for Off-Highway Motor Grader Equipment

02-19-01-0001

7/23/2025

Rollover protective structures (ROPS) that absorb energy during vehicle rollovers play a crucial role in providing integrated passive safety for operators restrained by seat belts. These protective structures, integrated into the vehicle frame, are designed to absorb high-impact energy and deform in a controlled manner without intruding into the occupant’s safe zone. This research focuses on the detailed analytical design procedure and performance evaluation criteria of the two-post open ROPS used on motor graders against lateral loads. An experimental test on a standard tubular square hollow section (SHS) column subjected to lateral load has demonstrated a significant correlation between the post-yield behavior of plastic hinge development and energy absorption, compared with results from various formulations adopted in finite element analysis (FEA). To reduce design iteration time and the cost of physical destructive testing, the complete equipment experimental setup is virtually simulated, building upon a thorough understanding of plastic hinge formation on columns under large deflections. This simulation provides comprehensive insights into the structural elasto-plastic response and employs the nonlinear implicit and explicit schemes of FEA to accurately predict energy absorption and force vs deflection behavior. The study follows the guidance outlined in ISO 3471: 2008 standard specifications, validating key structural performance parameters through virtual CAE simulation to ensure alignment with the standard’s force and energy requirements. The research emphasizes the control of merging empirical and analytical methods with advanced CAE tools, allowing engineers to design and evaluate ROPS with superior energy absorption and minimal deflection. By adopting this holistic approach, designers can significantly enhance ROPS structural integrity, ensuring improved safety and protection for operators in the demanding conditions of off-highway vehicles.

J., Avinash

Power Hop Detection in High-Torque Vehicles: A Machine Learning Approach with Focus on Data Coverage and Model Generalization

2025-01-0271

7/2/2025

Power hop is a vibration phenomenon that occurs during high accelerations from low speed. In severe cases it can lead to component damage or deformation. Therefore, the affected vehicles must be safeguarded against these vibrations by a safe design of the components and by additional software-based functions. Conventional software-based solutions, such as Traction Control Systems (TCS), often perform delayed interventions and apply harsh torque adjustments that reduce driving comfort. Motivated by these challenges, this paper proposes a novel approach for power hop detection in a high-torque vehicle based on Long Short-Term-Memory Network (LSTM) and real-time measurements. Unlike conventional methods, our LSTM precisely detects the start of power hop, enabling proactive torque adjustments. Due to its impact on vehicle stability, the model must achieve a high level of reliability and robustness. Given the importance of data quality in Machine Learning (ML), we consider data-related principles outlined in ISO/PAS 8800. First, the data acquisition through multiple driving tests is described. Second, two datasets are extracted and analyzed for representativeness and variability using k-Nearest Neighbors (kNN) and Dynamic Time Warping (DTW) to ensure broad coverage. Third, to evaluate the impact of the dataset variability on model generalization, these datasets are used to train two LSTMs. The results show that a dataset with higher variability in time series improves model generalization on unseen data.

Chehoudi, Moatez, Moisidis, Ioannis, Sailer, Marc, Peters, Steven

Commercial Vehicle’s Exhaust Front Pipe Reliability Improvement through Virtual Simulation and Experimental Validation

2025-01-0209

6/16/2025

The exhaust front pipe is a critical structural component in commercial vehicles, ensuring the leak-proof flow of exhaust gases into the exhaust after-treatment system while withstanding engine and frame vibrations. To isolate these vibrations, the front pipe is equipped with a flex connector capable of enduring various displacements at frequencies between 8-25 Hz. The position of the flex connector relative to the engine crank axis significantly impacts its structural reliability over its service life. This paper compares the existing design, which features a horizontally positioned flex connector, with a modified design that positions the flex connector vertically and changes the material from SS-304 to SS-321. Finite element analysis was conducted using Nastran software. The fatigue life of the existing flex connector design is approximately 1015 cycles. In contrast, the improved design demonstrates a fatigue life of 1727 cycles, representing a 70% increase in durability compared to the existing design. The newly designed front pipe was then evaluated under the worst-case excitation conditions of 25 mm lateral displacement at 8 Hz frequency using experimental setup. A correlation was established between virtual simulations and experimental validations. Virtual and experimental results conclude that there is a 70% increase in front pipe life when the flex connector is placed vertically with respect to the engine crank axis and SS-321 is used for the flex connector material. This finding is recommended for consideration during vehicle design development.

Chandel, Kushal, Paroche, Sonu, Namdev, Akhilesh, Jain, Shailendra, Patil, Keyur

Flap-Lag Stability Analysis of RACER in High-Speed Flight conditions

F-0081-2025-0226

5/20/2025

By its seventh flight after the first take-off, the RACER (Rapid And Cost-Effective Rotorcraft) demonstrator smoothly reached the targeted 220kts speed in stabilized forward flight, validating the high-speed compound architecture developed by Airbus Helicopters in the frame of Clean Sky 2 programme. During the flight envelope exploration, the dynamic behavior of the main rotor was carefully assessed, by monitoring the vibratory loads and validating its aeroelastic stability. Particular care was taken to validate the predicted stability domain of the Dual Rotor phenomenon, a particular case of flap-lag coupling associated with high-speed flight conditions. This paper presents the most significant results shaping the success of RACER flight test campaign. After having introduced the theoretical background and the associated analytical equations, the simulation framework based on the comprehensive analysis tool STORM is presented to discuss the numerical resolution of the stability problem. Then, the rotor dynamics loads and airframe vibratory behavior of RACER are closely examined to demonstrate the absence of any sign of instability, in the various flight conditions offered by its rotor and wing configuration. At last the flight test results are compared to the computed stability domain to assess the margins and estimate the high-speed potential of the rotorcraft.

Skladanek, Yan, Coisnon, Remi, Ferullo, David

Airbus RACER High Speed Demonstrator Flight Tests

F-0081-2025-0182

5/20/2025

Developed in the frame of the European Clean Sky 2 program, the RACER High Speed Helicopter Demonstrator of Airbus performed its maiden flight on April 25th, 2024. In the continuity of the previous high-speed demonstrator X3 (1st flight in 2010) the RACER is a 7/8t (15000 / 18000 lb) class compound helicopter powered by two SHE Aneto-1X engines, including a wing and two propellers. The tail rotor is removed as the two propellers control the yaw axis by differential thrust. At flight 07, with its initial default settings, it reached a true airspeed of 227 kts in level flight, exceeding its objective of 220 kts.

Eglin, Paul, Embacher, Martin, Desvigne, Damien, Roca-Leon, Enric

Structural Strength Evaluation of the Lightweight Frame of Bus Passenger Seat with High-Tensile Material and Analysis of the Importance of Independent Variables by Regression

02-18-04-0022

5/10/2025

This study aims to develop a lightweight bus passenger seat frame by conducting structural nonlinear finite element analysis (FEA) on various thickness combinations of seat frame components to identify the optimal configuration. The thicknesses of critical structural members that primarily bear the load when force is applied to the seat frame were selected as independent variables, while stress on each component and compliance with ECE R14 seatbelt anchorage displacement regulations were set as dependent variables. A regression analysis was performed to calculate the importance of each component and analyze the influence of each design variable on the dependent variables. Strain gauges were attached to critical areas of the actual seat frame to conduct a seatbelt anchorage test, and simulations under identical conditions were performed using the nonlinear FEA software (LS-DYNA) to validate the reliability of the analysis results. The optimized seat frame exhibited a maximum stress of 734 MPa and a displacement of 300.5 mm, satisfying the ECE R14 compliance criteria. A total of 81 scenarios with varying thickness combinations for the seat frame components were generated, and the results of each scenario were used to analyze the importance of design variables on the seat frame’s structural strength. The regression model achieved an R2 value of 0.927, confirming its reliability in predicting the structural response. These findings contribute to the development of optimized lightweight seat frames that enhance both safety and weight efficiency in commercial vehicles.

Ko, Yeong Gook, Cho, Kyu Chun, Lee, Ji Sun, Kang, Ki Weon

Reducing LiDAR Cabin Noise with Damped Elastomers a Novel Method for Predicting Performance and Durability

2025-01-0114

5/5/2025

Mechanical light detection and ranging (LiDAR) units utilize spinning lasers to scan surrounding areas to enable limited autonomous driving. The motors within the LiDAR modules create vibration that can propagate through the vehicle frame and become unwanted noise in the cabin of a vehicle. Decoupling the module from the body of the vehicle with highly damped elastomers can reduce the acoustic noise in the cabin and improve the driving experience. Damped elastomers work by absorbing the vibrational energy and dispelling it as low-grade heat. By creating a unique test method to model the behavior of the elastomers, a predictable pattern of the damping ratio yielded insight into the performance of the elastomer throughout the operating temperature range of the LiDAR module. The test method also provides an objective analysis of elastomer durability when exposed to extreme temperatures and loading conditions for extended periods of time. Confidence in elastomer behavior and life span was restored when no signs of performance degradation were present after 30 simulated years of normal loading conditions at extreme temperatures.

Russell, Casey, Masterson, Peter, O'Connell, Kerry

Localisation of Ultra-Short Sound Emissions from Automotive Components by Using the Sound Field Scanning Method

2025-01-0092

5/5/2025

Design verification and quality control of automotive components require the analysis of the source location of ultra-short sound events, for instance the engaging event of an electromechanical clutch or the clicking noise of the aluminium frame of a passenger car seat under vibration. State-of-the-art acoustic cameras allow for a frame rate of about 100 acoustic images per second. Considering that most of the sound events introduced above can be far less than 10ms, an acoustic image generated at this rate resembles an hard-to-interpret overlay of multiple sources on the structure under test along with reflections from the surrounding test environment. This contribution introduces a novel method for visualizing impulse-like sound emissions from automotive components at 10x the frame rate of traditional acoustic cameras. A time resolution of less than 1ms eventually allows for the true localization of the initial and subsequent sound events as well as a clear separation of direct from reflected sound. The measurement instrumentation uses a rotating linear array of a few digital microphones which granularly scans the incident sound field on a circular area. The proposed method for computing an acoustic image is based on compensating the moving microphone signals for Doppler distortions and evaluating the coherence of the resulting signals with a non-moving reference microphone for each point in the acoustic image. The methodology is evaluated in the context of localizing the periodic engage event of an electromechanical clutch and the clicking noise of the aluminium frame of a passenger car seat under periodic excitation.

Rittenschober, Thomas

The Applications of Acoustic Black Holes to Attenuation of Coach/Bus Frame Structure Vibrations

2025-01-0065

5/5/2025

Basic structures of vehicle frames、aircraft fuselages and ship hulls are made of beams、columns and trusses. If Acoustic Black Holes(ABH) are carefully arranged alongside with the wave propagation paths in those structures, the wave propagation paths could be changed at NVH engineers’ will and the structure vibrations can be reduced. Two kinds of ABHs are used in this paper: one is ABH made of Polyurethane(PU), other one is ABH composed of several steel plate 1D ABH stacked up in parallel. Three structures are used to test the effectiveness of ABHs for vibration reductions: a squared hollow sectional steel commonly used in motorcoach/bus chassis and frame structures, a simple frame for motorcoach airbag suspension and a 12m chassis structure. The attached ABHs show a great vibration attenuation in terms of transfer functions on the basic structure element for a motorcoach. The lateral, vertical and longitudinal transfer functions for steel ABHs were greatly reduced from 13.2~14.7 dB. Then test was extended to a simple frame that is common structure for motorcoach airbag suspension. The results show that ABHs have3.6~6.3 dB vibration attenuations. Based on those tests, the ABHs were also added to a 12-meter motorcoach chassis frame. The ABHs were attached at rear left upper disk for airbag suspension and at the seat fixing bolt area, the transfer function from the airbag suspension upper disk to seat fixing bolt area was reduced about 3dB. These effective vibration reductions show the great capabilities of ABHs to attenuate the structure vibrations for motorcoach and bus and ABHs could play a crucial role in attenuating structural vibration, structural noise radiation and structure-borne noise in motorcoach and bus.

Xu, Chuanyan, Wang, Jianjun, Xing, Qisen, Chen, Hengbin, Huang, Xianli

Optimization of Gusset Geometry for Racecar Frame Design

2025-01-5033

5/1/2025

This research optimizes sheet metal gusset geometry to support a suspension pickup point in a Formula SAE racecar. The sheet metal gusset design incorporates an external radial cut-out and an internal triangular cut-out, each of which can be adjusted in size to optimize the stiffness to mass ratio. A finite element analysis was set up using a heavy braking load case, which applied 3900 N to the suspension point being supported by the gusset. A parametric optimization (finite element analysis) was run in SolidWorks to gather mass and stiffness data for each of the 143 designs under the prescribed load case. The parametric optimization was run on both a simulated front hoop and a test fixture, which showed a similar trend in their results. Experimental testing was performed on three designs. The gusset profiles were waterjet and TIG welded to the test fixture tube frames. The results of the test agreed with the simulation results with a discrepancy of less than 10% in all cases. The results of the parametric optimization were then analyzed using the Karush–Kuhn–Tucker (KKT) optimization method in MATLAB and an optimal design set was found. Any design in this set has the minimum mass for its given stiffness. This process can be used to determine the design with the maximum stiffness/mass ratio for any given stiffness requirement and is accurate to within 10% of the simulated value. The optimization method is not limited to specific gusset geometry and can be used to reduce the mass of any gusset with known loading conditions.

Burggraf, Jacob, Willerth, Stephanie Michelle, Yu, Bosco

Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces

2024-32-0046

4/18/2025

The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on uneven roads. These stress points consistently appeared near the connection of the rear shock absorber. This analysis not only minimizes the need for extensive real-vehicle testing but also swiftly identifies structural weaknesses, reducing both time and costs. It provides valuable insights for design optimization, serving as a key reference for future product development in the industry.

Chiou, Yi-Hau, Hwang, Hsiu-Ying, Huang, Liang-Yu

Prediction Method of Strength Robustness Affected by Arc Welding Sectional Dimensions

2024-32-0038

4/18/2025

The arc welding process is essential for motorcycle frames, which are difficult to form in one piece because of their complex shapes, because a single frame has dozens of joints. Many of the damaged parts of the frames under development are from welds. Predicting the strength of welds with high reliability is important to ensure that development proceeds without any rework. In developing frames, CAE is utilized to build up strength before prototyping. Detailed weld shapes are not applicable to FE models of frames because weld shapes vary widely depending on welding conditions. Even if CAE is performed on such an FE model and the evaluation criteria are satisfied, the model may fail in the actual vehicle, possibly due to the difference between CAE and actual weld bead geometry. Therefore, we decided to study the extent to which the stresses in the joint vary with the variation of the weld bead geometry. Morphing, a FE modeling method and design of experiment method, was utilized to derive the distribution of stress variation in the joint for each dimension of the weld bead shape (throat thickness, leg length, flank angle, etc.). The number of calculations would be enormous if every combination of weld bead dimension values were considered exhaustively. Therefore, the “Latin Hypercube Sampling (LHS)” [1] method of design of experiments can be used to reduce the number of combinations while distributing the probability of occurrence of parameters in a full distribution. Using these methods, the influence of weld quality on frame strength was clarified within a feasible computation time.

Hada, Yusuke, Sugita, Hisayuki

Analysis of the Effect of Combination Frame Flexibility on Weave Modes

2024-32-0049

4/18/2025

The weave mode of a motorcycle is known to be affected by the flexibility of the vehicle frame. The weave mode has been shown to be more unstable in the 10-DOF model than in the 4-DOF model. However, it is not clear why the weave mode would be unstable, given the six different frame flexibilities. In this study, the authors analyzed the stability of the weave mode in a 4-DOF model when the same was integrated with two types of frame flexibilities. In the vehicle specifications used in the analysis, the combination of the bending flexibility of the front forks and the torsional flexibility of the main frame destabilizes the weave mode. The analysis results show that the phase delay of the front tire lateral force is caused by the phase delay of the steering angle. The combined bending flexibility of the front forks and the torsional flexibility of the main frame results in a large phase lag in the steering angle.

Haraoka, Reiya, Katayama, Tsuyoshi, Yoshino, Takahiko

A Low-Entry Bus Body Structure Performance under the Conditions of the New Car Assessment Program Frontal Crash Tests

09-13-02-0007

4/9/2025

The New Car Assessment Program (e.g., US NCAP and EuroNCAP) frontal crash tests are an essential part of vehicle safety evaluations, which are mandatory for the certification of civil means of transport prior to normal road exploitation. The presented research is focused on the behavior of a tubular low-entry bus frame during a frontal impact test at speeds of 32 and 56 km/h, perpendicular to a rigid wall surface. The deformation zones in the bus front and roof parts were estimated using Ansys LS-DYNA and considered such factors as the additional mass (1630 kg) of electric batteries following the replacement of a diesel engine with an electric one. This caused stabilization of the electric bus body along the transverse axis, with deviations decreased by 19.9%. Speed drop from 56 to 32 km/h showed a reduction of the front window sill deformations from 172 to 132 mm, and provided a twofold margin (159.4 m/s2) according to the 30g ThAC criterion of R80. This leads to the conclusion about the recommendation to reduce the regulatory NCAP speed for city buses to ensure a sufficient safety margin, especially considering the city speed limit of 40–50 km/h. The novelty consists in the application of the NCAP regulations, which is not typical for buses, with the formation of conclusions about the higher danger for passengers compared to UNECE R29 due to the much deeper penetration of plastic deformations into the bus body (up to the rear axle). The obtained results can influence accident prevention strategies and the revision of the city bus certification approaches and regulations.

Holenko, Kostyantyn, Dykha, Aleksandr, Koda, Eugeniusz, Kernytskyy, Ivan, Royko, Yuriy, Horbay, Orest, Berezovetska, Oksana, Rys, Vasyl, Humeniuk, Ruslan, Berezovetskyi, Serhii, Chalecki, Marek

Compatibility between Stability and Curving Ability of Railway Vehicles Using Conventional and Unconventional Bogie Frame Models

02-18-03-0014

4/9/2025

This article analyses the fundamental curving mechanics in the context of conditions of perfect steering off-flanging and on-flanging. Then conventional, radial, and asymmetric suspension bogie frame models are presented, and expressions of overall bending stiffness kb and overall shear stiffness ks of each model are derived to formulate the uniform equations of motion on a tangent and circular track. A 4 degree of freedom steady-state curving model is formulated, and performance indices such as stability, curving, and several parameters including angle of attack, tread wear index, and off-flanging performance are investigated for different bogie frame configurations. The compatibility between stability and curving is analyzed concerning those configurations and compared. The critical parameters influencing hunting stability and curving ability are evaluated, and a trade-off between them is analyzed. For the verification, the damped natural frequencies and mean square acceleration response (MSAR) of the mathematical model are analyzed with the same determined from the finite element model and experimental test, respectively. The results determined from mathematical and finite element simulation and experimental tests are found to be similar; therefore, the formulated mathematical model is verified.

Sharma, Rakesh Chandmal, Sharma, Sunil Kumar, Palli, Srihari, Rallabandi, Sivasankara Raju, Sharma, Neeraj

Structural Seam Weld Optimization with Efficient Approach of DFSS

2025-01-8248

4/1/2025

In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout each phase of IDDOV. Three case studies are presented in this paper to demonstrate that the presented DFSS approach provides efficient, effective, and reliable practices to improve the robustness of weld designs over conventional design methodologies. This practice approach is scalable not just within the automotive industry but across other industries applying welded components.

Qin, Wenxin, Li, Fan, Pohl, Kevin J., Pentapati, Venkat

Hierarchical Feature-Based Localization Using Scene Graphs in Off-Road Navigation

2025-01-8046

4/1/2025

While numerous advancements have been made in autonomous navigation for structured indoor and outdoor environments, these solutions often do not generalize well to off-road settings. There are unique challenges in such settings such as unreliable GPS, limited computational and memory resources, and sparse environmental features, making navigation particularly difficult. In our work, we propose a novel data structure called Hierarchical Dynamic Scene Graphs (HDSG) to address these challenges. HDSG captures environmental information at different resolutions, integrating both geometric and semantic features. It enables various navigation tasks such as localization, loop closure, and human interaction through the visualization of environmental features for remote operators. We evaluated the performance of localizing a robot’s position within the world frame by comparing compact spatial descriptors extracted from semi-consecutive scene graphs, derived from 3D LiDAR point clouds. Compared to directly applying traditional Iterative Closest Point (ICP) algorithms on point clouds, our approach demonstrates that localization on scene graphs is more efficient and accurate. In evaluations using the RELLIS-3D dataset, the HDSG is constructed in at most 5 seconds using only commodity hardware. The overall memory footprint of the HDSG is very compact accounting for only 450-500 MB. Moreover, using the HDSG for robot localization has demonstrated faster and more precise results than using traditional ICP approaches directly on the input point cloud. These results highlight the potential of scene graph-based localization to deliver faster, more memory-efficient, and more accurate performance in unstructured off-road environments, showing a promising foundation for future enhancements and applications.

Alam, Fardifa Fathmiul, Luricich, Federico, Li, Nianyi, Jia, Yunyi, Li, Bing

Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System

2025-01-8268

4/1/2025

Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring, resulting in the determination of the coefficients for each segment and the coordinates of the transition points in the fitting function. The total weighted root mean square (RMS) value of the cab floor acceleration was used as the optimization objective, while the coefficients and the coordinates of the breakpoints in the fitting function were employed as optimization variables. A multi-island genetic algorithm was applied to optimize the cab suspension's stiffness and damping properties. The optimization results indicate that the enhanced suspension system contributes to an improvement in cab ride comfort.

Hao, Qi, Zhu, Yuntao, Sun, Wen, Sun, Kai, Sun, Zhiyong, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin

A Time-Aware Shaper-Based Method for Addressing Traffic Bursts and Out-of-Order Induced by IEEE 802.1CB in In-Vehicle Networks

2025-01-8079

4/1/2025

The trends of intelligence and connectivity are continuously driving innovation in automotive technology. With the deployment of more safety-critical applications, the demand for communication reliability in in-vehicle networks (IVNs) has increased significantly. As a result, Time-Sensitive Networking (TSN) standards have been adopted in the automotive domain to ensure highly reliable and real-time data transmission. IEEE 802.1CB is one of the TSN standards that proposes a Frame Replication and Elimination for Reliability (FRER) mechanism. With FRER, streams requiring reliable transmission are duplicated and sent over disjoint paths in the network. FRER enhances reliability without sacrificing real-time data transmission through redundancy in both temporal and spatial dimensions, in contrast to the acknowledgment and retransmission mechanisms used in traditional Ethernet. However, previous studies have demonstrated that, under specific conditions, FRER can lead to traffic bursts and out-of-order, which are intolerable for safety-critical applications. Current research has analyzed the causes of traffic bursts and out-of-order delivery, but effective preventive solutions have yet to be proposed. To address these issues, this paper first employs a formal method to demonstrate that intermittent streams cannot satisfy the conditions for generating traffic bursts and out-of-order delivery. Subsequently, a novel intermittent stream constraint is proposed and basic constraints for time-aware shaper (TAS) are extended to support redundant communication. Finally, a TAS-based method is implemented, which ensures that traffic is shaped into intermittent streams when FRER is used. Simulation results in OMNET++ indicate that the TAS-based method proposed effectively avoids traffic bursts and out-of-order issues after recovery from link failures.

Luo, Feng, Ren, Yi, Zhu, Yian, Wang, Zitong, Guo, Yi, Yang, Zhenyu

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