Browse Topic: Bodies and Structures

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Segment Manipulator Retrofit2025-01-0159To be published on 04/25/2025
A segment manipulator machine was in service nineteen years. Many of the control components were out of date and hard to obtain. Customer engaged Electroimpact to upgrade using the latest state-of-art controls. The program from the previous control system could not be reused. A “layup mandrel” is a form that is used to lay carbon fiber. The layup mandrel for a wide body aircraft fuselage section consists of six segments. The mandrel is made up of segments so that it can be assembled and disassembled from the inside. The segments are Crown, Upper Left, Upper Right, Lower Left, Lower Right, and Keel. For each build the mandrel is assembled with a segment manipulator machine, wound with carbon fiber tape, clad, and baked in an autoclave. Then the mandrel is disassembled with a segment manipulator machine leaving the cured carbon fiber shell behind. The segments are refurbished and brought to the assembly area on segment carts for the next build. Segments each weigh in the vicinity of 3000
Luker, Zachary, Donahue, Michael
Technical Paper
Innovative High-Performance Active Dampers for Effective Mitigation of Helicopter Main Rotor Vibrations2025-01-0163To be published on 04/25/2025
Helicopter vibrations, primarily generated by the main rotor-gearbox assembly, are a major source of concern due to their impact on structural integrity, cockpit instrument durability, and crew comfort. These vibrations are mainly transmitted through the gearbox’s rigid support struts to the fuselage, leading to increased cabin noise and potential damage to critical components. This paper presents a solution for vibration mitigation which involves replacing traditional gearbox support struts with low-weight, high-performance active dampers. Developed by Elettronica Aster S.p.A., these active dampers are designed as electro-hydraulic actuators embedded within a compliant structure. The parallel nested configuration of the system enables high power densities and effective vibration control, significantly reducing the transmission of harmful vibrations to the fuselage. The comprehensive model-based design process is detailed, describing the development and use of a high-fidelity physics
Bertolino, Antonio Carlo, Sorli, Massimo, Porro, Paolo Giovanni, Galli, Claudio
Technical Paper
A New Test Rig for Electrically Actuated Landing Gear and Brake of a Small Transport Aircraft2025-01-0161To be published on 04/25/2025
Performing highly representative tests of aircraft equipments is a critical feature for gaining utmost confidence on their ability to perform flawlessly in flight under the entire spectrum of operating conditions. This can also contribute to accelerate the certification process of a new equipment. A research project (E-LISA) was performed in recent years, as part of the european funded Clean Sky 2 framework, with the objective of building an innovative facility for testing an electrically actuated landing gear and brake for a small air transport. The project eventually led to the development and construction of an Iron Bird able to reproduce in a realistic and comprehensive way a full variety of landing test cases consistent with certification specifications and landing histories available in the repository of the airframer. The Iron Bird that was eventually developed is a multi-functional intelligent and easy reconfigurable facility integrating hardware and software allowing to
De Martin, Andrea, Jacazio, Giovanni, Bertolino, Antonio
Technical Paper
Empirical Inflow Ratio Adjustment for Hovering Open Rotors with Experimental Validation2025-01-0162To be published on 04/25/2025
This study presents empirical modifications of Blade Element Momentum Theory (BEMT) to improve rotor performance prediction for open rotors in hovering conditions. The empirical adjustments were made to the inflow ratio, factoring in the real rotor wake area and estimated induced power losses. A comparison between experimental data and two analytical models, one using an empirical inflow formula and the other a theoretical formula (classical BEMT), was conducted for two rotors. The empirical inflow model demonstrated superior accuracy in predicting thrust and torque. These modifications are applied to the inflow ratio by accounting for the actual rotor wake area and estimated induced power losses. The findings highlight the potential for more accurate performance prediction through the integration of empirical data into theoretical frameworks.
Dayhoum, Abdallah, Ramirez-Serrano, Alejandro, Martinuzzi, Robert
Technical Paper
INTEGRATED BODY STRUCTURE TO ACCOMMODATE MANUAL AND POWER DOOR SUNSHADE VARIANTS IN A VEHICLE2025-01-8616To be published on 04/01/2025
Door Sunshade in a vehicle has proven to be very comfortable and luxurious feature to the customers. Luxury vehicles provide Power Sunshade which is electrically operated with the activation of a switch, whereas cost conscious vehicles provide manual sunshade which requires manual coiling and uncoiling. This study is to develop a Door Panel structure that can accommodate both the Manual Sunshade and Power Sunshade, thereby serving both cost conscious as well as luxury seeking customers. Manual Sunshade consists only of cassette, Pull Bar, Spindle Mechanism and Hooks whereas the power sunshade consists of Cassette, Pull Bar, Spindle Mechanism, Flap mechanism, Bowden Cable Mechanism, Actuator and Motor. Due to this difference in Package, it becomes difficult to accommodate both Variants of Sunshade into the same body system. However, this study helps in developing a common body structure by ways of effective Packaging, Modifying the cable and Actuator Mechanism and critical packaging of
S M, Rahul, d, Anantha, Kakani, Phani Kumar
Technical Paper
Evaluation of Several Tesla Dashcam Angles for Model 3 and Y Via Reverse Project Photogrammetry2025-01-8700To be published on 04/01/2025
Tesla Model 3 and Model Y vehicles come equipped with a standard dash-camera feature with the ability to record video in four directions called TeslaCam. Additional views have been known to be recorded under specific circumstances, often triggered in impacts, and available to some owners through data requests to Tesla. Prior research into TeslaCam either did not fully explore all known camera views across multiple vehicles or the metadata associated with genuine copies of TeslaCam video. Testing and analysis of real-world crashes revealed a reliable methodology to conducting photogrammetry analysis utilizing the front, rear, and side cameras found on Tesla Model 3 and Model Y vehicles, how to verify the likelihood of any copy of TeslaCam being a genuine original video discovered during the course of an investigation, and how to examine ever changing video properties as new software becomes available for the vehicles. Moving and stationary Tesla vehicles captured frames of GPS
Jorgensen, Michael, Swinford, Scott, Imada, Kevin, Farhat, Ali
Technical Paper
Predicting Forming Limit of Hot Stamping Boron Steel using a Modified Zener-Hollomon Parameter based Ductile Failure Criterion2025-01-8225To be published on 04/01/2025
This study combines a recently proposed ductile failure criterion with a modified Zener-Hollomon parameter to predict the forming limit of a boron steel at hot stamping temperatures. The Zener-Hollomon parameter is modified to include a parameter that accounts for the non-linear variation of strain rate during hot stamping. The combined ductile failure criterion takes into account the critical damage at localized necking or at fracture as a function of strain path, initial sheet thickness and strain rate variation. The process of determining various parameters in the failure criterion is explained. The capability of the ductile failure criterion is demonstrated by predicting forming limit of a boron steel in an isothermal Nakajima dome test. The criterion is further demonstrated by predicting fracture in hot stamping a B-Pillar part (NUMISHEET Benchmark #3 2008).
Sheng, ZiQiang, Mallick, Pankaj
Technical Paper
Accuracy of Time Stamps in Digital and Network Video Recorders2025-01-8690To be published on 04/01/2025
Video analysis plays a major role in many forensic fields. Many articles, publications, and presentations have covered the importance and difficulty in properly establishing frame timing. In many cases, the analyst is given video files that do not contain native metadata. In other cases, the files contain video recordings of the surveillance playback monitor which eliminates all original metadata from the video recording. These “video of video” recordings prevent an analyst from determining frame timing using metadata from the original file. However, within many of these video files, timestamp information is visually imprinted onto each frame. Analyses that rely on timing of events captured in video may benefit from these imprinted timestamps, but for forensic purposes, it is important to establish the accuracy and reliability of these timestamps. The purpose of this research is to examine the accuracy of these timestamps and to establish if they can be used to determine the timing
Molnar, Benjamin, Terpstra, Toby, Voitel, Tilo
Technical Paper
Validation of SynthEyes for use in Collision Reconstruction2025-01-8688To be published on 04/01/2025
Accurate reconstruction of vehicle collisions is critical for understanding incident dynamics and informing safety improvements. Traditionally, vehicle speed from dashcam footage has been approximated by estimating the time duration and distance traveled as the vehicle passes between reference objects. This method limits the resolution of the speed profile to an average speed over given intervals, minimizing vehicle accelerations. A more detailed speed profile can be calculated by tracking the vehicle’s position in each video frame; however, this method is time-consuming, can introduce positional error and variable frame rate noise, and is often constrained by the availability of external trackable features in the surrounding environment. Motion tracking software, widely used in the visual effects industry to track camera positions, has been adopted by some collision reconstructionist for determining vehicle speed from video. This study examines the accuracy and reliability of using
Perera, Nishan, Griffiths, Harrison, Prentice, Greg
Technical Paper
Hierarchical Feature-based Localization using Scene Graphs in Off-road Navigation2025-01-8046To be published on 04/01/2025
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
Alam, Fardifa Fathmiul, Luricich, Federico, Li, Nianyi, Jia, Yunyi, Li, Bing
Technical Paper
A Study on Reconstructing In-Cylinder Combustion Images Based on Local Images2025-01-8381To be published on 04/01/2025
The current leading experimental platform for engine visualization research is the optical engine, which features transparent window components classified into two types: partially visible windows and fully visible windows. Due to structural limitations, fully visible windows cannot be employed under certain complex or extreme operating conditions, leading to the acquisition of only local in-cylinder combustion images and resulting in information loss. This study introduces a method for reconstructing in-cylinder combustion images from local images using deep learning techniques. The experiments were conducted using an optical engine specifically designed for spark-ignition combustion modes, capturing in-cylinder flame images under various conditions with high-speed cameras. The primary focus was on reconstructing the flame edge, with in-cylinder combustion images categorized into three types: images where the flame edge is fully within the partially visible window, partly within the
Wang, Mianheng, Zhang, Yixiao, Du, Haoyu, Xiao, Ma, Mao, Jianshu, Fang, Yuwen
Technical Paper
The Accuracy of Vehicle Speeds, Decelerations, and Brake Onset Times Calculated from Onboard Dash Cameras2025-01-8691To be published on 04/01/2025
The goal of this study was to evaluate the influence of camera and video parameters on the accuracy of speeds and decelerations calculated from onboard dashboard cameras (“dashcams”). We equipped a single test vehicle with 5 commercially available dashcams. We also equipped the test vehicle with a 5th-wheel, a brake pedal switch, and a synchronization light visible to the dashcams. We conducted 9 emergency braking tests from about 60 km/h and calculated the reference speed and deceleration from the 5th-wheel data. The brake pedal switch indicated the moment of brake application. The light synchronized the dashcam videos to the 5th-wheel and brake pedal data. The 5 dashcams had horizontal fields of view (FOV) ranging from 120 to 170 degrees, frame rates of 30 or 60 frames per second (FPS), and resolutions of 1080p, 2K, or 4K. For each camera and brake test, we extracted the video from the dashcam and calculated its linear and rotational motion using SynthEyes, a 3D motion tracking and
Flynn, Thomas, Ahrens, Matthew, Young, Cole, Siegmund, Gunter P.
Technical Paper
Propulsion System Design of Cadillac Lyriq Electric Vehicle2025-01-8566To be published on 04/01/2025
The design and development of EVs and HEVs has become a growing issue recently due to concerns about pollution and dependence on non-renewable fossil fuels. Accordingly, General Motors (GM) has an evolving vehicle electrification plan over the past several decades and into the future to deliver low-cost and efficient EVs. The propulsion system of GM-Cadillac's first electric vehicle, the Lyriq, is designed to deliver significant improvements in both range and peak performance. Its propulsion system uses an optimized drive unit consisting of interior permanent magnet (IPM) motors and silicon traction inverters. The main objective of the drive unit design was to minimize energy loss and cost while maximizing hardware consolidation, range, performance, power density and scalability. Two IPM motors are designed with different stack lengths and number of stator turns, while keeping the rotor design and stator conductor profiles the same. The larger motor is used in rear-wheel drive (RWD
Momen, Faizul, Jensen, William, He, Song, Chowdhury, Mazharul, Zahid, Ahsan, Forsyth, Alexander, Alam, Khorshed, Anwar, Mohammad, Kim, Young
Technical Paper
A Minimalist High-Power Boost Charging Solution Integrated Into Electric Drives2025-01-8560To be published on 04/01/2025
The drive power and charging performance of leading electric vehicles (EVs) continue to advance, with high-performance EVs elevating their high-voltage platform ranges from below 500V to 800V and even 900V. To be compatible with existing public charging stations of lower voltage, vehicles with high-voltage platforms often equip a boost charge device. However, this boost charge device incurs additional costs, weight, and space requirements. Most mature solutions employ an additional DC-DC boost converter, which, however, results in low charging power at a high cost. Some new approaches utilize the power switching devices and motor inductance of electric drives to form a boost converter circuit, using a three-phase current in-phase control strategy for charging. This method requires external inductors to reduce charging current ripples. Alternatively, to minimize current ripple without external inductors, a two-phase parallel and one-phase series topology is used, albeit at the expense
Yuan, Baocheng, Ma, Yong, Xie, Xi, Liu, Shaowei, Guan, Tianyu, Ge, Kai, Zheng, Lifu, Xu, Xu
Technical Paper
Optimal Autonumous Steering Control Design and Trajectory Planning for Towbarless Aircraft Taxiing System2025-01-8293To be published on 04/01/2025
Efficient and safe aircraft scheduling scheme is of great significance to the construction of smart airport. The towbarless aircraft taxiing system is a common dispatching method, which is composed of the towbarless towing vehicle and the aircraft. In order to increase the steering accuracy and the efficiency and safety of dispatching, the autonomous steering control and trajectory planning of the system are studied. In this paper, the towbarless aircraft taxiing system is transformed into tractor-trailer system, and the kinematic model of the aircraft tractor is established. A force sensor is installed at the joint of the tractor and the aircraft wheel to obtain the force acting on the tractor. Taking the tractor as a virtual subsystem of towbarless aircraft taxiing system, and it is regarded as the controlled object of path tracking. An improved reference trajectory generation method based on two-layer optimal control is developed to generate reference trajectories. In the first
Zhu, Hengjia, Zhao, Zhouqiao, Xu, Yitong, Zhang, Wei
Technical Paper
Efficient Simulation of Multi-Body Dynamics with Roller Guide Joints Using Julia2025-01-8285To be published on 04/01/2025
Due to the existence of nonlinearities in mechanical systems, considerable concern has arisen regarding the effectiveness of solving multi-body dynamics (MBD) problems. Although simulations of traditional mechanisms with perfect joints could be solved with high efficiency, joints in practical applications are often characterized by clearances, leading to a significant reduction in simulation efficiency for such cases. Enhancing the effectiveness of solvers is essential for simulating systems with nonlinearities. This paper presents an exploration of using Julia, a high-performance, open-source programming language, to solve MBD problems based on index-1 differential-algebraic equations (DAE). Quaternions were utilized to represent the orientation of the rigid bodies. Alongside the modelling of common perfect joints, both planar perfect and imperfect roller guide joints were included to illustrate the method's adaptability in addressing non-standard joint types. Two case studies were
Tong, Jiachi, Meng, Dejian, Lian, Yubo, Gao, Yunkai, Yang, James
Technical Paper
Adapting the Technology Readiness Level (TRL) Framework to AV Development2025-01-8671To be published on 04/01/2025
The technological advancements in the automotive industry have seen a significant leap with the introduction of ADS-Equipped Vehicles (AVs), with potential for enhanced safety, efficiency, and convenience. As the development of an AV transitions from the stages of conceptual design to deployment, assessing the maturity of the technology through a structured framework is crucial. This paper proposes the adaptation of the Technology Readiness Level (TRL) framework originally developed by NASA (and adopted widely in a variety of industries) to the AV industry to provide a consistent, understandable, and transparent method to describe an AV product’s state of development. The TRL framework is mated to the existing Safety Case Framework (SCF) developed in the Automated Vehicle – Test and Evaluation Process (AV-TEP) Mission, a collaboration between Science Foundation Arizona and Arizona State University. Advancing from one TRL to the next is argued through the satisfaction of requirements
Swaminathan, Sunder, Wishart, Jeffrey, Zhao, Junfeng, Russo, Brendan, Rahimi, Shujauddin
Technical Paper
Investigation of flow structures in different body types contributing to drag change due to crosswind2025-01-8767To be published on 04/01/2025
To reduce aerodynamic drag during real world driving, it is important to consider the effect of crosswinds. In this study, we investigated the differences in flow structures between an SUV and a notchback to understand the mechanism behind the difference in yaw angle dependence of Cd value when a quasi-steady yaw angle is applied. In this study, simulations and wind tunnel tests were performed for the SUV and the notchback with yaw angles of 0°, 2°, and 5°. The indicator of flow structure analysis were crossflow and total pressure, and the results of wind tunnel tests and simulations were visualized, focusing on rear wake. In addition, iso-surfaces and path lines around the vehicle were visualized in detail, using the results of simulations. These results revealed the differences in flow structures depending on the body type. In the case of the notchback, the main vortex at yaw angle zero is behind the C-pillar. When a yaw angle is applied, this becomes stronger on both the leeward and
Nakata, Akihiro, Okamoto, Satoshi, Nishida, Shuhei, Morikawa, Yosuke, Nakashima, Takuji
Technical Paper
The aerodynamics development of the Range Rover2025-01-8781To be published on 04/01/2025
The New Range Rover is the fifth generation of this luxury SUV. With a drag coefficient of 0.30 at launch, it was the most aerodynamically efficient luxury SUV in the world. This aerodynamic efficiency was achieved by applying the latest science. Rear wake control was realised with a large roof spoiler, rear pillar and bodyside shaping, along with an underfloor designed to reduce losses over a wide range of vehicle configurations. This enabled manipulation of the wake structure to reduce drag spread, optimising emissions measured under the WLTP regulations. Along with its low drag coefficient, in an industry first, it was developed explicitly to achieve reduced rear surface contamination with reductions achieved of 70% on the rear screen and 60% over the tailgate when compared against the out-going product. This supports both perceptions of luxury along with sensor system performance, demonstrating that vehicles can be developed concurrently for low drag and reduced rear soiling. This
Chaligné, Sébastien, Gaylard, Adrian Philip, Simmonds, Nicholas, Turner, Ross
Technical Paper
Material selection of a Parcel shelf for structural performance and Perceived quality improvement through an assessment of wide range composite and sustainable materials.2025-01-8249To be published on 04/01/2025
In passenger vehicles, a parcel shelf is used to conceal luggage in the trunk compartment. Conventionally, materials used in new product development are heavy, making products less competitive in the market. As the automotive industry increasingly prioritizes lightweight products for EV, it is essential to find new alternative materials and technologies that meet performance standards and add value to the product. This research paper focuses on weight optimization, sustainable material section and cost reduction of the parcel shelf without compromising durability, stiffness, and load-bearing capabilities. The proposed material consists of ultra-lightweight composite materials available in various GSM and thicknesses, offering a high strength-to-weight ratio that contributes to: 1. Improved load vs. deflection ratio. 2. Enhanced aesthetics and perceived quality. The proposed material combination and strategy for the parcel shelf will result in a product that is half the weight of
Kinthala, Nareen Kumar, Patnaik, Manga, Khandelwal, Mohit, Kakani, Phani Kumar, Palaniappan, Elavarasan
Technical Paper
Headliner design considerations to meet safety and regulations2025-01-8245To be published on 04/01/2025
Headliners are one of the largest components inside an automobile, stretching from the front windshield to the rear windshield. Besides its aesthetic purpose, it contributes to multiple other purposes like housing different components, helps in NVH, defines the interior roominess, and plays a crucial role in defining the deployment of curtain airbag. The headliner also plays a role in meeting regulatory requirements like upward visibility and headroom requirements of the occupants. During the deployment of curtain airbag, it is important that the headliner-pillar interface aids in the easy opening of airbag, with the least hindrance. This is defined by multiple factors like the location of headliner-pillar interface in “z” direction, and its distance from the airbag ramp bracket, the position of the inflator, the mountings of the headliner and pillar trims, to name a few. Also, during the deployment of the airbag, it is important that parts such as grabhandle, speaker grilles, etc
Sabesan, Arvind Kochi, D., Anantha, Kakani, Phani Kumar
Technical Paper
Correlation of Vehicle drop test in front & rear wheel landing condition using multibody dynamics simulations2025-01-8638To be published on 04/01/2025
Two wheelers motorcycles are used for many purposes e.g. commuting from place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require large suspension strokes to absorb large oscillations due to road conditions. These motorcycles undergo jumps of different heights and different vehicle orientations. In some of the dynamic situations front wheel may land first than the rear and in some of the situations rear may land first as compared to front. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed at component test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same load case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test
Jain, Arvind Kumar, Nirala, Deepak
Technical Paper
Establishment of Failure Simulation Models for Bonding of Carbon Fiber Laminated Skins and Cores in Monocoque Structures Based on Formula Student Racing Cars2025-01-8006To be published on 04/01/2025
In Formula SAE , the primary function of the frame is to provide structural support for the different components and withstand the applied load. Traditional truss steel tube body have drawbacks such as low strength and high weight, which has led most Formula Student teams worldwide to adopt monocoque made of carbon fiber composites, which are lighter and stronger. Enhancing the mechanical performance of carbon fiber laminates has been a key focus of research for these teams. In three point bending tests of carbon fiber laminates, the outer skin is primarily subjected to tensile forces. This results in significant stress at the adhesive layer between the skin and the core material at both ends of the laminate, leading to potential adhesive failure. Consequently, experimental boards often exhibit delamination between the outer skin and the core material, and premature core crushing, which compromises the mechanical performance of the laminate and fails to pass the Structural Equivalency
Ning, Zicheng
Technical Paper
Integrated Bracket Design Optimizations to Resolve Issues in Vehicle Prototype Stage2025-01-8614To be published on 04/01/2025
Integrated bracket is a plastic part which packages functional components such as ADAS, Rain Light Sensor and the mounting provisions of auto dimming IRVM. This part is fixed on the windshield of an automobile using double sided 3M tapes and glue. ADAS, rain light sensor and auto dimming IRVM play an important part in the safety of driver, and everyone present in the automobile. The paper takes the readers through a concern faced by the authors that emphasizes the importance of the combination and location of tapes and glues on the integrated bracket. The 3M tapes at the B side of the integrated bracket are used to locate it on the windshield and hold it until the glue's curing time gets completed. If the combination and positions of glue and tapes is not optimum, then the bracket will get peeled off from the windshield causing aesthetic deterioration. This concern came in the prototype stage of a Mahindra SUV. In this concern, the integrated bracket was peeling off from the windshield
Chandravanshi, Priyansh, Dharmatti, Girish
Technical Paper
Computer aided engineering for sound propagation in exterior environments2025-01-8631To be published on 04/01/2025
Physical testing is required to assess multiple vehicles in different conditions, specially to validate those related to regulations. The acoustic evaluations have difficulties and limitations in physical test; cost and time represent important considerations every time. Additionally, the physical validation happens once a prototype has been built, this takes place in a later phase of the development. Sound pressure is measured to validate different requirements in a vehicle, horn sound is one of these and it is related to a regulation of united nations (ECE28). Currently the validation happens in physical test only and the results vary depending on the location of the horn inside the front end of every vehicle. In this article, the work for approaching a virtual validation method through CAE is presented with the intention to get efficiency earlier in product development process.
Alonso, Liliana, Cruz, Raciel, Alvarez, Ezequiel
Technical Paper
Research on the Boundary of Pedestrian Leg Impactor Test in Low-Speed Passive and Active Conditions2025-01-8735To be published on 04/01/2025
With the widespread application of the Automatic Emergency Braking System (AEB) in vehicles, its impact on pedestrian safety has received increasing attention. However, after the intervention of AEB, the kinematic characteristics of pedestrian leg collisions and their corresponding biological injury responses also change. At the same time, in order to accurately evaluate the pedestrian protection performance of vehicles, the current assessment regulations generally use advanced pedestrian protection leg impactors (aPLI) and rigid leg impactors (TRL) to simulate the movement and injury conditions of pedestrian legs. Based on this, in order to explore the collision boundary conditions and changes in injury between vehicles and APLI and TRL leg impactors under the action of AEB, this paper first analyzes the current passive and active assessment conditions. Secondly, the simulation software LS-DYNA is used to build a finite element model of APLI and TRL impactor-vehicle collisions to
Ye, Bin, Hong, Cheng, Wan, Xinming, Liu, Yu, Cheng, James, Long, Yongchen, Hao, Haizhou
Technical Paper
Design and Evaluation of a Conceptual Zero-Emission Truck Model Considering Aerodynamic Efficiency2025-01-8784To be published on 04/01/2025
Emerging zero-emission-powertrain concepts are providing opportunities to re-shape heavy trucks for improved aerodynamic performance. To investigate the potential for energy savings through aerodynamic improvements, with a goal to inform operators and regulators of such benefits, a multi-phase project was initiated to design and evaluate aerodynamic improvements for Class 8 tractor-trailer combinations. While the focus was battery-electric and hydrogen-fuel-cell powered trucks, improvements for internal-combustion powered trucks were also examined. Previously-reported activities included a scaled-model wind-tunnel test that demonstrated the potential for up to 9% drag reduction from simple shape adaptations, with a follow-up CFD study providing guidance towards further optimization. This paper presents wind-tunnel-test results using a high-fidelity 30%-scale model of a new aerodynamic tractor concept, with comparison to a conventional North American Class 8 tractor with a modern
Ghorbanishohrat, Faegheh, McAuliffe, Brian, O'Reilly, Harrison
Technical Paper
Lattice based Localized Energy Absorber for Improved Vulnerable Road User Performance for a Vehicle2025-01-8723To be published on 04/01/2025
A passenger vehicle hood is designed to meet Vulnerable Road User (VRU) regulatory requirements and Consumer metric targets. Generally, hood inner design and its reinforcements, along with deformable space available under the hood are the main enablers to meet the Head Impact performance targets. However, cross functional balancing requirements like hood stiffness and packaging space constraints can lead to higher Head Injury Criteria (HIC) scores, particularly when secondary impacts are present. In such cases, a localized energy absorber is utilized to absorb the impact energy to reduce HIC within the target value. The current localized energy absorber solutions include the usage of flexible metal brackets, plastic absorbers etc. which has limited energy absorbing capacity and tuning capability. This paper focuses on usage of a novel 3D printed energy absorbers, based on various kind of lattice structures. These absorbers are either sandwiched between hood inner and the outer or are
Kinila, Vivekananda, Agarwal, Varun, V S, Rajamanickam, Tripathy, Biswajit, Gupta, Vishal
Technical Paper
Investigation of Skin Friction Topology on the AeroSUV Using GLOF Meter2025-01-8782To be published on 04/01/2025
In this study, the aerodynamics and skin flow field of a 1/5 scale SUV vehicle model called “AeroSUV” were experimentally investigated. The aerodynamics and skin flow field investigations were carried out in the wind tunnel at Hiroshima University with a Reynolds number ReL = 1.2×10^6, baseline yaw angle β = 0° and crosswind conditions β = 5°, 10° and 15° for two rear ends, Estateback and Fastback. The results provide aerodynamic information and detailed skin flow field information for a standard middle-class SUV vehicle with different rear ends, which is important for automotive design. By applying GLOF measurements to automotive aerodynamics, the skin friction topology was revealed in detail as skin flow field information that is useful for understanding the physics of the flow. The skin friction topology clearly shows the separation lines, reattachment lines, and focus points associated with the separation flow, longitudinal vortices and recirculation vortices of this vehicle model
Hijikuro, Masato, Shimizu, Keigo, Nakashima, Takuji, Hiraoka, Takenori
Technical Paper
Simulating the DrivAer Notchback Car Model using Wall-Function LES2025-01-8777To be published on 04/01/2025
This paper summarizes work on the application of a new and fully parallelized native GPU-based finite-volume solver on the DrivAER Notchback configuration using a wall-function LES approach. A series of meshes generated using a Rapid-Octree strategy have been investigated, and results for drag, surface pressure coefficient and velocity profile are compared with available experimental data.
Menter, Florian, Dalvi, Ashwini, Flad, David, Sharkey, Patrick
Technical Paper
STUDY ON THE IMPROVEMENT OF PEDESTRIAN AND VEHICLE VISIBILITY BY GEOMETRIC PATTERNS PROJECTION LIGHTING2025-01-8663To be published on 04/01/2025
A high percentage of pedestrian fatalities in traffic accidents occur at night. Although using high beams at night can enhance pedestrian visibility for drivers, it also presents the issue of increased glare for pedestrian. In this study, the researchers devised a geometric patterns projection lighting using projection technology, designed to reduce glare for pedestrians while enhancing the visibility of pedestrians and approaching vehicles. This study explores the effectiveness of a geometric patterns projection lighting compared to traditional Low beam and High beam headlights in enhancing pedestrian visibility during nighttime driving conditions. Conducted at Dynamic Research Inc.'s closed-course facility, the experiment involved 20 drivers who were exposed to each headlight type while performing specific tasks, including headlight noticeability, glare assessment, and pedestrian detection. The geometric patterns projection lighting, characterized by dynamic intersecting light
Kawamura, Kazuyuki, Oshida, Kei
Technical Paper
A Survey of Vehicle Forward Lighting System Mounting Height and Driver Eye Height2025-01-8662To be published on 04/01/2025
Headlight glare remains a persistent problem to the U.S. driving public. Over the past 30 years, vehicle forward lighting systems have evolved dramatically in terms of styling and lighting technologies used. Importantly, vehicles driven in the U.S. have increased in size during this time as the proportion of pickup trucks and sport-utility vehicles (SUVs) has increased relative to passenger sedans and other lower-height vehicles. Accordingly, estimates of typical driver eye height and the height of lighting equipment on vehicles from one or two decades ago are unlikely to represent the characteristics of newer vehicles in the U.S. automotive market. In the present study we surveyed the most popular vehicles sold in the U.S. and carried out evaluations of the heights of lighting systems, as well as typical driver eye heights based on male and female drivers. These data may be of use to those interested in understanding how exposure to vehicle headlighting and other factors have changed
Bullough, John D.
Technical Paper
Development of Ceramic Humidity Regulator (CHR) Using Honeycomb Type PTC Heater to Improve Electric Vehicle Driving Range in Winter2025-01-8177To be published on 04/01/2025
With Rapid growth of Electric Vehicles (EVs) in the market, challenges such as driving range, charging infrastructure, and reducing charging time needs to be addressed. Unlike traditional Internal combustion vehicles, EVs have limited heating sources and primarily uses electricity from the running battery, which reduces driving range. Additionally, during winter operation, it is necessary to prevent window fogging to ensure better visibility, which requires introducing cold outside air into the cabin. This significantly increases the power consumption for heating and the driving range can be reduced to half of the normal range. This study introduces the Ceramic Humidity Regulator (CHR), a compact and energy-efficient device developed to address driving range improvement. The CHR uses a desiccant system to dehumidify the cabin, which can prevent window fogging without introducing cold outside air, thereby reducing heating power consumption. A desiccant system typically consists of two
Hamada, Takafumi, Shinoda, Narimasa, Konno, Yoshiki, Ihara, Yukio, Ito, Masaki
Technical Paper
Study on relative displacement in assembly structure sections for Pre-validation of door trim noise2025-01-8618To be published on 04/01/2025
The importance of the pre-validation process for door trim noise is being emphasized as noise criteria have been heightened due to the transition to electric vehicles. The validation process currently uses SNRD (Squeak and Rattle Director) simulation to verify BSR through relative strain values. However, this process has the limitation of being time-consuming. To solve this issue, we have enhanced the efficiency of the process by creating a database of relative displacement values that occur based on the cross-section and structural characteristics of matching parts, enabling BSR validation using only cross-sectional and structural information.
Cho, Wonhyung, Na, Hyunghyun, Kim, Donghyeon, Kim, JongSoo, Shin, Dongwan
Technical Paper
Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery2025-01-8154To be published on 04/01/2025
The life of power battery and its discharge efficiency in electric cars will be significantly reduced in a low temperature environment. Therefore, in order to ensure its working mileage and safety, heating the power battery is required. Heat pump air conditioners and PTC-based onboard heaters are usually way to heat the power battery under lower temperature so far. In low temperature environment, due to the lower heating efficiency of the heat pump air conditioner, onboard heaters are widely used in electric cars. A specific thick film heater(TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is established. The heat transfer and fluid performace of the TFH is analied using a computational fluid dynamics software. The performance of TFH is measured on a test bench, and the measured data is used to validate the developed model. Using the established model, the heating efficiency of TFH is studied for different inlet
Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin
Technical Paper
A Time-Aware Shaper-Based Method for Addressing Traffic Bursts and Out-of-Order Induced by IEEE 802.1CB in In-Vehicle Networks2025-01-8079To be published on 04/01/2025
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
Luo, Feng, Ren, Yi, Zhu, Yian, Wang, Zitong, Guo, Yi, Yang, Zhenyu
Technical Paper
Research and structural optimization of lattice core based on monocoque of Formula Student racing car2025-01-8003To be published on 04/01/2025
Monocoque is a kind of integrated shell structure technology, which has gradually become the primary choice for various racing teams to make car bodies because of its advantages of small specific gravity and high specific strength. The unit of the monocoque is a carbon fiber composite sandwich structure, which is composed of two layers of carbon fiber skin inside and outside and core material between them. The inner and outer layers of the carbon fiber skin are stacked with carbon fiber composite materials of different directions and types. In this project, we plan to optimize the shape of the monocoque shell using the surface design software Alias, select core materials of different materials and structures, more advanced layups, and obtain feasible layup sequences and core material types through Hypermesh simulation and Matlab collaborative optimization, which will be verified by three-point bending experiments and circumferential shear experiments. Different from the previous
Cheng, Zhu H., Liu, JJ
Technical Paper
Barrier Weight Prediction for Vehicle Compatibility in North America Market using Finite Element Analysis2025-01-8621To be published on 04/01/2025
The proliferation of the electric vehicle (EVs) in the US market led to an increase in the average vehicle weight due to the integration of the larger high-voltage (HV) batteries. To comply with this weight increase and meet stringent US regulations and Consumer Ratings requirements, Vehicle front-end rigidity has substantially increased. This increased stiffness in the larger vehicles (Large EV pickups/SUVs) may have a significant impact during collision with smaller vehicles. To address this issue, it is necessary we consider adopting a vehicle compatibility test like EuroNCAP MPDB in North American market as well. This study examines the influence of mass across vehicle classes and compares the structural variations for each impact class. The EuroNCAP MPDB (Moving Progressive Deformable Barrier) protocol was referenced for this analysis. Our evaluation approach comprises of two sections: the impact of the barrier mass on to the vehicle structure (V2B) and vehicle-to-vehicle impact
Kusnoorkar, Harsha, Koraddi, Basavaraj, Guerrero, Michael, Sripada, Venu Vinod, Tangirala, Ravi
Technical Paper
Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System2025-01-8268To be published on 04/01/2025
Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established. 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
Hao, Qi, Zhu, Yuntao, Sun, Wen, Sun, Kai, Sun, Zhiyong, Huang, Yu, Zhen, Ran, Shangguan, Wen-Bin
Technical Paper
Effects of Aging on PVC-based Instrument Panel Skin for Passenger Airbag Deployment Analysis2025-01-8321To be published on 04/01/2025
Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin material
G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar
Technical Paper
Regression Model based Method for Stiffness Design of Laminated Glasses2025-01-8320To be published on 04/01/2025
There has been a growing interest in laminated sidelites (or door glasses) in automotive for the benefits of both security and comfort. Current standard products are a 2.1/0.76/2.1 mm construction with soda-lime glass symmetrically distributed on each side of a PVB layer. Due to low shear stiffness of PVB, the standard laminate has a significantly reduced flexural rigidity in comparison to a monolith with the same total thickness. A novel lightweight laminate concept with ultrathin chemically strengthened glass was developed by Corning [1]. This concept considered asymmetrical designs with thinner (0.5 – 1.1 mm) chemically strengthened Corning® Gorilla® Glass laminated to relatively thick outer ply of conventional soda-lime glass and was found to provide enhanced stiffness over standard symmetrical laminate designs of same total thickness. It is known that flexural rigidity of laminated glass depends on multiple variables, such as shape, load distribution and boundary constraining
Yu, Chao, Cleary, Thomas, Joubaud, Laurent, kister, Evan, Fisher, W Keith
Technical Paper
Structural Weld Optimization with Efficient Approach of DFSS2025-01-8248To be published on 04/01/2025
Structural Weld Optimization with Efficient Approach of DFSS Abstract In automotive engineering, welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weakest 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
Qin, Wenxin (Daniel)
Technical Paper
A Modified Johnson-Cook Model Considering Strain-Temperature Coupling for Welding Simulation of Aluminum Alloy Bumper2025-01-8243To be published on 04/01/2025
The metal inert-gas (MIG) welding technique employed for aluminum alloy automotive bumpers involves a complex thermo-mechanical coupling process at elevated temperatures. Attaining a globally optimal set of model parameters continues to represent a pivotal objective in the pursuit of reliable constitutive models that can facilitate precise simulation of the welding process. In this study, a novel piecewise modified Johnson-Cook (MJ-C) constitutive model that incorporates the strain-temperature coupling has been proposed and developed. A quasi-static uniaxial tensile model of the specimen is constructed based on ABAQUS and its secondary development, with model parameters calibrated via the the second-generation non-dominated sorting genetic algorithm (NSGA-II) method. A finite element simulation model for T-joint welding is subsequently established, upon which numerical simulation analyses of both the welding temperature field and post-welding deformation can be conducted. The results
Yi, Xiaolong, Meng, Dejian, Gao, Yunkai
Technical Paper
Integrated design for body in white fabricated by additive manufacturing and its mechanical performance analysis2025-01-8613To be published on 04/01/2025
With the development of additive manufacturing technology, the concept of integrated design has been introduced and deeply involved in the research of body design. In this paper, by analyzing the structural characteristics of the electric vehicle body, we designed a body in white with the additive manufacturing process, and analyzed its mechanical properties through finite element method. According to the structural characteristics of the body, the integrated structure was modeled in three dimensions using CATIA. For the mechanical properties of the body, the strength and stiffness of the body structure were simulated and analyzed based on ANSYS Workbench. The results show that for the strength of the body, the maximum stress of the simulation results was compared with the permissible stress, and the maximum stress was calculated to be less than the permissible stress under each working condition. For the body stiffness, the displacement of the body deformation was used to measure, and
Xu, Cheng, Zhang, Ming, Wang, Tao, Zhang, Tang-yun, Cao, Can, Wang, Liangmo
Technical Paper
Automated Analysis and Cleaning of Manufacturing Data: The Power of Automation Playbooks2025-01-8332To be published on 04/01/2025
High-efficiency manufacturing relies heavily on an extensive suite of software applications, including those for order handling, quality control, trace management, PLC communication, Andon boards, and scheduling. This reliance is particularly pronounced in facilities operating under tight schedules with stringent production targets and close collaboration with Just-In-Time (JIT) suppliers. Ensuring the continuous operation of these software systems is crucial; any downtime can result in delayed or lost units, potentially leading to significant revenue losses amounting to millions annually. Regular patching and rebooting of servers and applications are essential to maintaining system uptime, as the risk of failure increases with prolonged operation. Therefore, frequent resets and health checks are necessary, but these processes are both complex and time-consuming due to the multitude of servers and narrow scheduling windows involved. The integration of automation into these maintenance
Jan, Jonathan, Preston, Joshua, Juncker, John
Technical Paper
Rough Road Vehicle dynamics analysis for vehicle vibration assessment2025-01-8306To be published on 04/01/2025
Multibody dynamics analysis in vehicle development provides a few useful vehicle design guidelines in a few disciplines. The first discipline is vehicle handling simulation, where the major recommendation is suspension geometry and tuning of bushings, shocks and springs. The vehicle dynamics simulations on rough roads give insights about vehicle durability performance: vehicle components, subsystems, and the vehicle body systems. Almost all inputs to the vehicle systems come from tire to ground interactions, tire modeling is the most critical aspect in vehicle durability simulation, e.g. load prediction. The third discipline is the vehicle vibration performance assessment using vehicle dynamic simulations. This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model is simulated on ride roads, first. Hardware measurement can be done in a similar fashion to get the vehicle target performance or bench marking data
Hong, Hyung-Joo, Maddula, Pavan Kumar, Jun, Hyochan
Technical Paper
Tests for Signal and Marking Devices Used on Vehicles 2032 mm or More in Overall WidthJ2139_202503 (Historical)03/05/2025
This SAE Recommended Practice provides standardized laboratory tests, test methods, and performance requirements applicable to signal and marking devices used on vehicles 2032 mm or more in overall width.
Heavy Duty Lighting Standards Committee
Recommended Practice
Effects of Emergency Vehicle Warning Lighting System Characteristics on Driver Perception and Behavior09-13-01-000302/28/2025
Secondary crashes, including struck-by incidents are a leading cause of line-of-duty deaths among emergency responders, such as firefighters, law enforcement officers, and emergency medical service providers. The introduction of light-emitting diode (LED) sources and advanced lighting control systems provides a wide range of options for emergency lighting configurations. This study investigated the impact of lighting color, intensity, modulation, and flash rate on driver behavior while traversing a traffic incident scene at night. The impact of retroreflective chevron markings in combination with lighting configurations, as well as the measurement of “moth-to-flame” effects of emergency lighting on drivers was also investigated. This human factors study recruited volunteers to drive a closed course traffic incident scene, at night under various experimental conditions. The simulated traffic incident was designed to replicate a fire apparatus in the center-block position. The incident
D. Bullough, John, Parr, Scott, Hiebner, Emily, Sblendorio, Alec
Journal Article
Windshield Wiper Systems - Trucks, Buses, and Multipurpose VehiclesJ198_202502 (Current)02/25/2025
This SAE Recommended Practice establishes testing methods and performance requirements for windshield wiping systems on trucks, buses, and multipurpose passenger vehicles with a GVWR of 4500 kg (10000 pounds) or greater and light-duty utility vehicles with a GVWR of less than 4500 kg (10000 pounds). The test procedures and minimum performance requirements outlined in this document are based on currently available engineering data. It is the intent that all portions of the document will be periodically reviewed and revised as additional data regarding windshield wiping system performance are developed.
Truck and Bus Windshield Wipers and Climate Control Comm
Recommended Practice
Windshield Defrosting Systems Test Procedure and Performance Requirements - Trucks, Buses, and Multipurpose VehiclesJ381_202502 (Current)02/25/2025
This SAE Recommended Practice establishes uniform test procedures and performance requirements for the defrosting system of enclosed cab trucks, buses, and multipurpose vehicles. It is limited to a test that can be conducted on uniform test equipment in commercially available laboratory facilities. For laboratory evaluation of defroster systems, current engineering practice prescribes that an ice coating of known thickness be applied to the windshield and left- and right-hand side windows to provide more uniform and repeatable test results, even though - under actual conditions - such a coating would necessarily be scraped off before driving. The test condition, therefore, represents a more severe condition than the actual condition, where the defroster system must merely be capable of maintaining a cleared viewing area. Because of the special nature of the operation of most of these vehicles (where vehicles are generally kept in a garage or warmed up before driving), and since
Truck and Bus Windshield Wipers and Climate Control Comm
Recommended Practice
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