Experimental testing in automotive development sometimes relies on ad hoc approaches like ‘One Factor at a Time’, particularly in time- and resource-limited situations. While widely used, these approaches are limited in their ability to systematically capture parameter interactions and system complexities, which poses significant challenges in safety-critical applications like high-voltage battery systems. This study systematically investigates the factors influencing thermal runaway in lithium-ion battery cells using a statistical full-factorial experimental design. Key parameters, including state of charge, cell capacity and heating trigger power, have been analyzed under controlled conditions with an autoclave setup, enabling precise measurement of thermal and mechanical responses. The use of automotive-grade lithium-ion cells ensures relevance for next-generation applications. By employing factorial regression and statistical analysis, the study identifies critical temperatures

Ceylan, Deniz, Kulzer, André Casal, Winterholler, Nina, Weinmann, Johannes, Schiek, Werner

Experimental and Numerical Analysis of Direct Injection Process for Hydrogen-Fuelled Internal Combustion Engines

2025-01-0307

07/02/2025

In the context of the clean transport sector, there has been growing interest in the use of hydrogen in internal combustion engines due to its potential to nearly eliminate all engine-out criteria pollutants, while maintaining high thermal efficiency through the use of a lean combustion process. In direct injection configurations, mixing process is significantly influenced by hydrogen jet dynamics. First, a comprehensive experimental campaign was conducted in a constant volume vessel to assess the performance of a hydrogen injector using the Schlieren technique. The jet behavior was analyzed by varying injector recess, injection pressure, and back pressure. Subsequently, the case study was replicated in a 3D Computational Fluid Dynamics (CFD) environment, addressing the complexities associated with modeling under-expanded jets. The model was first validated against experimental data, both in terms of jet morphology and through three geometric indices. Then, a simplified simulation

Pucillo, Francesco, Piano, Andrea, Millo, Federico, Giordana, Sergio, Rapetto, Nicola, Vargiu, Luca

Optimisation of Rotor Skewing of a Yokeless and Segmented Armature Axial Flux Machine

2025-01-0311

07/02/2025

This paper presents an optimisation approach for rotor skewing in a Yokeless and Segmented Armature (YASA) design Axial Flux Machine (AFM) for electric vehicle applications. Torque ripple amplitudes are a critical factor influencing the noise, vibration and harshness (NVH) behaviour of electric motors. The focus of this paper is to reduce the torque ripple amplitudes of the dominant harmonics over the entire torque-speed characteristic of the AFM. The principle of the proposed approach is a segmented permanent magnet configuration of the AFM, where individual magnet segments can be circumferentially shifted to achieve optimal skewing configurations. Initial optimisations are performed using 2D finite element (FE) simulations, modelled as linear motors with multiple slices and different numbers of magnet segmentation. However, the accuracy of the 2D FE results is limited due to the lack of interaction between the individual segments and the insufficient representation of three

Müller, Karsten, Maisch, Hannes, De Gersem, Herbert, Burkhardt, Yves

Numerical Analysis of Direct-Injection and Combustion Inside a H2 Engine

2025-01-0301

07/02/2025

The direct injection of hydrogen (H2) inside internal combustion engines (ICEs) is gaining large research interest over the port-fuel injection strategy, because of several advantages as higher volumetric efficiencies, increased power output and reduced risks of abnormal combustion. However, the required high pressure ratios across the injector nozzle produce moderate-to-high under-expanded jets, characterized by complex flow structures. This poses a challenge for the numerical modelling of the mixture preparation by means of 3D computational fluid dynamics (CFD) approaches. In this work, a validated 3D-CFD methodology has been employed to simulate the closed-valve cycle of a direct injection H2 engine equipped with a centrally mounted hollow-cone injector and a non-axisymmetric piston bowl. First, injection and mixture preparation have been studied considering an early injection at the beginning of the compression stroke, and a delayed injection in the second half of the compression

Capecci, Marcolucio, Sforza, Lorenzo, Lucchini, Tommaso, D'Errico, Gianluca, Pezza, Vincenzo, Tosi, Sergio

Evaluation of Static and Dynamic Stiffness of Rubber Grommet by Experimental and FEA Method

2025-01-0274

07/02/2025

Vibration control is most important in automotive applications, and generally, rubbers are used to dampen these vibrations due to their inherent nature and low-cost manufacturing methods. Now, to select a rubber material, Shore hardness is considered in engineering applications, but to additionally control the behaviour, we need to understand its static and dynamic stiffness. These values help to determine the vibration isolation obtained by these rubbers. In this paper, we will discuss methods to calculate the static and dynamic stiffness of rubber grommets using experimental methods and FEA modelling. As elastomers have non-linear material properties, various material modelling techniques in FEA are used to capture multiple phenomena like creep, fatigue, and dynamic conditions. Rubber compounding is used in order to improve the physical and chemical properties, which in turn would give desirable linear characteristics. Certain guidelines and thumb rules are used in the rubber

Khamkar, Prasad Subhash, Gaikwad, Vikrant Chandrakant

Closed-Loop Real-Time Simulation of the Thermal and Electromagnetic Behavior in Electric Drive Trains: Optimizing Model Accuracy for Virtual Prototyping

2025-01-0320

07/02/2025

This paper presents a coupled electromagnetic and thermal simulation of Permanently Excited Synchronous Machines (PMSM) in the context of virtual prototyping in a real-time Hardware-in-the-Loop (HiL) environment. Particularly in real-time simulations, thermal influences are often neglected due to the increased complexity of a coupled simulation. This results in inaccurate simulations and incomplete design optimizations. The objective of this contribution is to enable a precise and realistic real-time simulation that represents the electromagnetic as well as the thermal behavior. The electromagnetic simulation is executed used a Field-Programmable Gate Array (FPGA) and parameterized by Finite Element Analysis (FEA) results. The thermal model is based on a Lumped-Parameter-Thermal-Network (LPTN), which is based on physical laws, geometry parameters and material specifications. The simulation results are validated with testbench measurements to ensure the accuracy of the overall model. By

Jonczyk, Fabian, Kara, Onur, Bergheim, Yannick, Lee, Sung-Yong, Strop, Malte, Prochotta, Fabian, Andert, Jakob

Noise, Vibration, and Harshness Countermeasures of Permanent Magnet Synchronous Motor with Viscoelastic Layer Material

10-09-04-0031

06/30/2025

An electric motor exhibits structural dynamic excitation at high frequency, making it particularly prone to noise, vibration, and harshness (NVH) problems. To mitigate this effect, this article discusses a novel countermeasure technique to improve NVH performances of electric machines. A viscoelastic rubber layer is applied on the outer surface of a permanent magnet synchronous motor (PMSM) as vibration damping treatment. The goal is to assess the countermeasure effectiveness in reducing acoustic emissions at different temperatures, through a combination of numerical modeling and experimental validation. A finite element model of the structure is realized, considering a viscoelastic material model for the rubber material, with frequency-dependent loss factor and storage modulus. The numerical model is validated by means of experimental modal tests performed on a house-built cylindrical structure, designed to mimic the geometry of a typical cooling jacket of a PMSM for automotive

Soresini, Federico, Barri, Dario, Ballo, Federico, Manzoni, Stefano, Gobbi, Massimiliano, Mastinu, Giampiero

Nonlinear Finite Element Calculation of Ultimate Breakage Load for Pyro-Inflator Housing

2025-01-5045

06/27/2025

Accurate prediction of the ultimate breakage pressure load for pyro-inflator housing is a critical aspect of inflator development. In this study, the tensile test of a specimen, from its initial shape to fracture, is simulated to verify the material properties of the inflator housing. The numerical results demonstrate high accuracy, with the tensile force–displacement curve, maximum tensile force, necking in the concentrated instability zone, fracture location, and inclined angle all closely matching the experimental data. Following material correlation, the ultimate breakage load of the inflator housing under hydrostatic burst test conditions is calculated using an explicit solver. A stress tensor state analysis method is proposed to define the ultimate load based on the onset of plastic instability in the thickness direction at the top center of the inflator. Compared to experimental results, the accuracy of the ultimate breakage pressure prediction using this method is 99.04%, while

Wang, Cheng

R-1234yf (HFO-1234yf) Recovery/Recycling/Recharging Equipment for Mobile Air-Conditioning Systems

J2843_202506 (Current)

06/17/2025

This SAE Standard applies to equipment to be used with R-1234yf refrigerant only. It establishes requirements for equipment used to recharge R-1234yf to an accuracy level that meets Section 9 of this document and purity levels defined in SAE J2099. Refrigerant service equipment is required to ensure adequate refrigerant recovery to reduce emissions and provide for accurate recharging of mobile air-conditioning systems. Equipment shall be certified to meet all performance requirements outlined in this document and international/regional construction and safety requirements as outlined in this document.

Interior Climate Control Service Committee

Assessment of the Skull Fracture Prediction Capability of Finite Element Head Models

2025-22-0005

06/16/2025

The development of drones has raised questions about their safety in case of high-speed impacts with the head. This has been recently studied with dummies, postmortem human surrogates and numerical models but questions are still open regarding the transfer of skull fracture tolerance and procedures from road safety to drone impacts. This study aimed to assess the performance of an existing head FE model (GHBMC M50-O v6.0) in terms of response and fracture prediction using a wide range of impact conditions from the literature (low and high-speed, rigid and deformable impactors, drones). The fracture prediction capability was assessed using 156 load cases, including 18 high speed tests and 19 tests for which subject specific models were built. The GHBMC model was found to overpredict peak forces, especially for rigid impactors and fracture cases. However, the model captured the head accelerations tendencies for drone impacts. The formulation of bone elements, the failure representation

Pozzi, Clément, Gardegaront, Marc, Allegre, Lucille, Beillas, Philippe

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

2025-01-0209

06/16/2025

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

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

Analysis of Combustion Characteristics of a Small 2-Stroke Opposed Piston Engine Using an Optically Accessible Engine and Numerical Analysis

2025-01-0223

06/16/2025

As global warming becomes more serious, decarbonization of internal combustion engines, which emit a large amount of carbon dioxide, is being promoted. It is predicted that many vehicles will still be equipped with engines in 2035, and a variety of powertrains will be required in the future. Therefore, we focused on the opposed-piston engine as an internal combustion engine specialized for power generation applications. The opposed-piston engine is characterized by its light weight due to the absence of a cylinder head, low S/V ratio due to the ultra-long stroke, reduced cooling loss due to the long stroke, and reduced vibration due to the offsetting of the reciprocating inertial forces of the left and right pistons. We believe that the engine for power generation can achieve the required high efficiency operation and vibration reduction. Therefore, in this study, combustion analysis of a two-stroke opposed-piston engine with features of low vibration, high efficiency, and high output

Yamazaki, Yoshiaki, Watanabe, Sou, Okawara, Ikumi, Otaki, Yusuke, Liu, Jinru, Iijima, Akira

Numerical Simulation and Parametric Optimization of Engine/Powertrain Mounts: Identifying Key Design Variables to Reduce NVH Noise

2025-01-0251

06/16/2025

Engine and powertrain mounts are vital for isolating vibrations and reducing the transmission of Noise, Vibration, and Harshness (NVH) from the engine to the vehicle structure. Despite technological advancements, addressing NVH issues related to tribological factors continues to pose significant challenges in automotive engineering. This study aims to systematically identify and optimize design parameters of engine/powertrain mounts to minimize NVH levels using CAE tools and parametric optimization techniques in Abaqus and Isight, respectively. The purpose of this research is to investigate the correlation between various design parameters of powertrain mounts and their impact on NVH characteristics. Specific attention is focused on noises such as clunking, banging, or thumping that emerge from the engine bay under dynamic conditions like acceleration, braking, or turning. These sounds often occur as the engine moves excessively due to worn mounts, making unintended contact with other

Ganesan, Karthikeyan, Seok, Sang Ho

Life Cycle Assessment of Hydrogen Generation through Steam Methane Reforming: A Focus on Co-Product Allocation between Steam and Electricity

2025-01-0181

06/16/2025

This research presents a numerical analysis of the environmental impacts associated with using hot steam as a co-product in hydrogen production through Steam Methane Reforming (SMR) of renewable gas sources. As hydrogen production technology advances rapidly, reducing emissions and addressing environmental concerns, particularly greenhouse gas (GHG) emissions, have become essential. This study examines the SMR process with a focus on the environmental effects of utilizing hot steam as a co-product for electricity generation or facility heating. The analysis evaluates renewable feedstocks, including landfill gas, animal waste, food waste, and wastewater sludge, to determine their viability for sustainable hydrogen production. Key pollutants, such as carbon monoxide and nitrogen oxides, along with GHGs, are assessed to identify the most environmentally advantageous feedstock options. This work aims to provide insights to promote sustainable hydrogen production practices.

Rosyadi, Ahmad Adib, Lim, Ocktaeck

Multi-Physics Coupling Analysis of Hybrid Stator Permanent Magnet Vernier Motor for Electric Vehicle Based on Halbach Array

14-14-02-0013

06/11/2025

In order to improve the output torque and power density of the in-wheel motor, a hybrid stator permanent magnet vernier motor (HSPMVM) is proposed based on the traditional single-tooth permanent magnet vernier motor (PMVM-I) and split-tooth permanent magnet vernier motor (PMVM-II). With the help of analytical method and finite element method, the three motors of PMVM-I, PMVM-II, and HSPMVM are compared and analyzed. It is proved that HSPMVM has higher output torque and lower torque ripple, and the amount of permanent magnet is also significantly reduced. In order to further improve the operating performance, the Halbach array is applied to the HSPMVM to form a new hybrid stator Halbach array permanent magnet vernier motor (HSHPMVM). The analysis results show that the HSHPMVM has a significant magnetic concentration effect, the torque is increased by 61.96%, and the torque ripple is reduced by 22.47%. The magneto-thermal two-way coupling analysis of HSHPMVM under rated conditions shows

Xiuping, Wang, Jingquan, Yu, Dong, Xu, Chuqiao, Zhou, Chunyu, Qu

Temperature Effect on the Rattle and Squeak Noise of Automotive Instrument Panel and Console

2025-01-5042

06/10/2025

In order to improve the comfort and perceptive quality of vehicle on the climate conditions worldwide, the temperature effect on rattle and squeak of instrument panel and console is studied under temperatures of −30°C, 23°C, and 60°C. First, the modal accuracy of finite element model is certificated by real vehicle test. The first global mode shapes are reciprocating rotation and reciprocating translation for instrument panel and console, respectively, corresponding to frequencies of 36.6 Hz and 29.6 Hz, which attain about 91% and 92.5% relative to the experiment values. Second, on basis of the “3σ” threshold of 0.27%, an assembly clearance in left instrument panel has non-negligible rattle risk under all temperatures. Another three clearances have no rattle risk but get rattle increase under temperatures of −30°C and 60°C. In addition, the rattle risk is increased around console end clearances at the temperature of 60°C. In other cases, the rattle risk is 0% or can be neglected. Third

Yang, Xiaoyu, Mu, Yongtao

Braking Force Distribution Strategy for Brake-by-Wire Systems: Enhancing Safety and Redundancy

10-09-03-0028

06/09/2025

Brake-by-wire (BBW) systems, characterized by fast response, high precision, ease installation, and simplified maintenance, are highly likely to become the future braking systems. However, the reliability of BBW is currently inferior to that of traditional hydraulic braking systems. Considering ECE R13 regulations, actuator reliability, and braking efficiency, this article first proposes a new braking force distribution strategy to prevent braking failure and enhance vehicle safety without modifying the actuator itself. The strategy reduces the operating frequency of rear actuators during low- and medium-intensity braking, thereby extending their service life and operational reliability. Then, the co-simulation model combining Simulink and AMESim was established for simulation validation based on direct drive braking actuator. Additionally, the real-vehicle test platform was built for typical braking scenarios. The simulation and experimental results show that this strategy

Li, Tianle, Gong, Xiaoxiang, He, Chunrong, Deng, Zhenghua, Zhang, Hong, Xu, Rong, He, Haitao, Wang, Xun, Zhang, Huaiyue

Investigation of Injury Risk Functions of THOR-AV 50th Percentile Male Dummy

2025-22-0004

06/05/2025

This research investigated injury risk functions (IRF) for the THOR-AV 50th percentile male dummy in accordance with ISO TS18506, focusing on areas with design changes. The IRF development utilized a combination of physical tests and finite element (FE) model simulations. For certain postmortem human subject test cases lacking physical dummy tests, the validated Humanetics THOR-AV FE model (v0.7.2) was used to quickly generate data, with the understanding that final IRFs based on full physical test data might offer greater accuracy. Log-logistic, log-normal, and Weibull survival functions were fitted with 95% confidence intervals. The Akaike Information Criterion, Goodman-Kruskal-Gamma, Area under the Curve of Receiver Operating Characteristic, and Quantile-Quantile plot were employed to assess the prediction strength and relative quality of the final IRF selections. Among the three survival distributions, the Weibull distribution provided the best fit. The lumbar Fz was identified as

Wang, Z. Jerry, Hu, George

Predictive Modeling of Surface Roughness, Tool Wear, and Cutting Temperature in High-Speed Turning under Sustainable Machining Environments

05-19-01-0007

05/24/2025

The utilization of Inconel 718 is increasing daily in stringent operating conditions such as aircraft engine parts, space vehicles, chemical tanks, and the like due to its physical properties such as maintaining strength and corrosion resistance at higher temperature conditions. Besides, Inconel 718 is one of the difficult materials for machining because of maintaining its strength at elevated temperature, which generates higher cutting force leading to observed multiple tool wear mechanisms that affect the surface quality; lower thermal conductivity of materials produces high temperature generation that impacts the tool performance by reducing tool life. In addition, the presence of carbides and high hardness of IN 718 affects the machining performance. Therefore, in this view, this article describes the effect of cutting environments and machining parameters on the machining of Inconel 718 and optimizes the cutting conditions for sustainable machining. Three input parameters namely

Mane, Pravin Ashok, Dhawale, Pravin A., Nipanikar, Suresh, Khadtare, Avinash N.

Evaluation of Occupant Injury Risk in a Transport Aircraft Crash Test Environment

02-18-02-0011

05/16/2025

Researchers at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) previously conducted a full-scale crash test of a Fokker F28 MK1000 aircraft to study occupant injury risks. The goal of the current study was to investigate the injury predictions of the Global Human Body Models Consortium (GHBMC) and Total Human Model for Safety (THUMS) occupant models in the tested aircraft crash condition and explore possible utilization of both human body models (HBMs) in this context. Eight crash conditions were simulated utilizing each of the models. The HBMs were positioned in two postures, a neutral upright posture with hands resting on the legs and feet contacting the floor and a braced posture with head and hand contact with the forward seat back. Head and neck injury metrics and lumbar vertebra axial force were calculated and compared for all simulations. Both HBMs reported similar kinematic responses in the simulated impact conditions. However, the GHBMC

Jones, Nathaniel, Putnam, Jacob, Untaroiu, Costin Daniel

Proposed Reformulation of Brain Injury Criteria (BrIC) Using Head Rotation-Induced Brain Injury Thresholds Simulated and Derived Directly from A Subhuman Primate Finite Element Model

2025-22-0003

05/13/2025

Recent studies have found that Brain Injury Criteria (BrIC) grossly overpredicts instances of real-world, severe traumatic brain injury (TBI). However, as it stands, BrIC is the leading candidate for a rotational head kinematics-based brain injury criteria for use in automotive regulation and general safety standards. This study attempts to understand why BrIC overpredicts the likelihood of brain injury by presenting a comprehensive analysis of live primate head impact experiments conducted by Stalnaker et al. (1977) and the University of Pennsylvania before applying these injurious conditions to a finite element (FE) monkey model. Data collection included a thorough analysis and digitization of the head impact dynamics and resulting pathology reports from Stalnaker et al. (1977) as well as a representative reconstruction of the Penn II baboon diffuse axonal injury (DAI) model. Computational modeling techniques were employed on a FE Rhesus monkey model, first introduced by Arora et al

Demma, Dominic R., Tao, Ying, Zhang, Liying, Prasad, Priya

Development of a Generic Nearside Impact Test Fixture for Evaluating In-Vehicle Crashworthiness of Wheelchairs

2025-22-0002

05/13/2025

Current voluntary standards for wheelchair crashworthiness only test under frontal and rear impact conditions. To help provide an equitable level of safety for occupants seated in wheelchairs under side impact, we developed a sled test procedure simulating nearside impact loading using a fixed staggered loading wall. Publicly available side impact crash data from vehicles that could be modified for wheelchair use were analyzed to specify a relevant crash pulse. Finite element modeling was used to approximate the side impact loading of a wheelchair during an FMVSS No. 214 due to vehicle intrusion. Validation sled tests were conducted using commercial manual and power wheelchairs and a surrogate wheelchair base fixture. Test procedures include methods to position the wheelchair to provide consistent loading for wheelchairs of different dimensions. The fixture and procedures can be used to evaluate the integrity of wheelchairs under side impact loading conditions.

Boyle, Kyle, Hu, Jingwen, Manary, Miriam, Orton, Nichole R., Klinich, Kathleen D.

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

05/10/2025

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

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

Influence of Strain Rate Effect on Mechanical and Crashworthiness Properties of CFRP Composite Structures

05-19-01-0002

05/06/2025

Composite materials are increasingly utilized in industries such as automotive and aerospace due to their lightweight nature and high strength-to-weight ratio. Understanding how strain rate affects the mechanical and crashworthiness properties of CFRP composites is essential for accurate impact simulations and improved safety performance. This study examines the strain rate sensitivity of CFRP composites through mechanical testing and finite element analysis (FEA). Experimental results confirm that compressive strength increases by 100%–200% under dynamic loading, while stiffness decreases by up to 22% at a strain rate of 50 s−1, consistent with trends observed in previous studies. A sled test simulation using LS-Dyna demonstrated that the CFRP crash box sustained an average strain rate of 46.5 s−1, aligning with realistic impact conditions. Incorporating strain rate–dependent material properties into the FEA model significantly improved correlation with experimental crashworthiness

Badri, Hesam, Jayasree, Nithin Amirth, Loukodimou, Vasiliki, Omairey, Sadik, Bradbury, Aidan, Lidgett, Mark, Page, Chris, Kazilas, Mihalis

Hybrid Approaches to Software Reliability: Evaluating and Enhancing Prediction Models

2025-01-5024

05/06/2025

Software reliability prediction involves predicting future failure rates or expected number of failures that can happen in the operational timeline of the software. The time-domain approach of software reliability modeling has received great emphasis and there exists numerous software reliability models that aim to capture the underlying failure process by using the relationship between time and software failures. These models work well for one-step prediction of time between failures or failure count per unit time. But for forecasting the expected number of failures, no single model will be able to perform the best on all datasets. For making accurate predictions, two hybrid approaches have been developed—minimization and neural network—to give importance to only those models that are able to model the failure process with good accuracy and then combine the predictions of them to get good results in forecasting failures across all datasets. These models once trained on the dataset are

Mahdev, Akash Ravishankar, Lal, Vinayak, Muralimohan, Pramod, Reddy, Hemanjaneya, Mathur, Rachit

Identification of Suspension Kingpin Alignment Parameters Based on Screw Axis Theorem and Differential Calculation Model

2025-01-5034

05/06/2025

This paper presents an analytical approach for identifying suspension kingpin alignment parameters based on screw axis theorem and differential calculation model. The suspension kingpin caster and inclination alignment parameters can produce additional tire force, which affects vehicle handling dynamics. In wheel steering process, the multi-link suspension control arms lead to movement of the imaginary kingpin, which can cause change in suspension kingpin alignment parameters. According to the structure mechanism of commercial vehicle multi-link independent suspension, the kinematics characteristics of imaginary kingpin were analyzed based on the screw axis theorem. The angular velocity and translation velocity vectors were calculated. In order to avoid the influence of bushing deformation, the unique differential identification model was established to evaluate the suspension kingpin alignment parameters, and the identification results were compared with the ADAMS/Car data. The

Ding, Jinquan, Hou, Junjian, Zhao, Dengfeng, Guo, Yaohua

Evaluation of Automotive Closure Design for High Frequency Acoustic Performance

2025-01-0049

05/05/2025

A good Noise, Vibration, and Harshness (NVH) environment in a vehicle plays an important role in attracting a large customer base in the automotive market. Hence, NVH has been given significant priority while considering automotive design. NVH performance is monitored using simulations early during the design phase and testing in later prototype stages in the automotive industry. Meeting NVH performance targets possesses a greater risk related to design modifications in addition to the cost and time associated with the development process. Hence, a more enhanced and matured design process involves Design Point Analysis (DPA), which is essentially a decision-making process in which analytical tools derived from basic sciences, mathematics, statistics, and engineering fundamentals are used to develop a product model that better fulfills the predefined requirement. This paper shows the systematic approach of conducting a Design Point Analysis-level NVH study to evaluate the acoustic

Ranade, Amod A., Shirode, Satish V., Miskin, Atul, Mahamuni, Ketan J., Shinde, Rahul, Chowdhury, Ashok, Ghan, Pravin

High-Fidelity NVH Model Development for Electric Motors Using Deep Learning and Machine Learning Algorithms

2025-01-0123

05/05/2025

Electric motor whine is a significant source of noise in electric vehicles (EVs). To improve the noise, vibration, and harshness (NVH) performance of electric propulsion systems, it is essential to develop a physics-based, high-fidelity stator model. In this study, a machine learning (ML) model is developed using an artificial neural network (ANN) method to accurately characterize the material properties of the copper winding, varnish, and orthotropic stator laminate structure. A design of experiments (DOE) approach using Latin hypercube sampling of parameters is implemented after evaluating alternative surrogate models. A finite element (FE) model is constructed using the nominal stator design parameters to train the ANN model using 121 DOE variables and 72,000 data points. The ML-trained ANN model is then verified to predict the driving point frequency response function (FRF) spectrum with reasonable accuracy. Subsequently, modal tests are conducted on the electric stator, and the

Rao, Bhyri Rajeswara, GSJ, Gautam, He, Song

A Comprehensive Evaluation of PU Foam Sealing for EV NVH Performance

2025-01-0120

05/05/2025

Low density polyurethane foam was first proposed as an alternative to expandable baffles and tapes for sealing vehicle body cavities towards the end of the last century. Despite several inherent advantages for cavity sealing, the high equipment cost of dispensing amongst other reasons, this technology has not spread as widely as expected. With the advent of electric vehicles, there is an increased emphasis on controlling higher frequencies from motors, inverters and other components, and polyurethane foam can be a viable solution by providing more robust sealing. Polyurethane foam sealing is already being employed in the new breed of electric vehicles, but its NVH advantages have not been fully studied or published in literature. Using an existing electric vehicle with conventional expandable baffles & tape sealing measures, a comprehensive evaluation of NVH performance using the closed-cell polyurethane foam solution was conducted. Testing included component level bench test on body

Kavarana, Farokh, Guertin, Bill

Effects of Acoustic Dissipative Material in Applications with Acoustic Leakage

2025-01-0117

05/05/2025

This paper investigates the performance of a dissipative material compared to conventional acoustic materials under conditions that simulate real-world vehicle applications with acoustic leakage. Various acoustic materials were evaluated through laboratory experiments, which included acoustic leakage in both the steel panel and the acoustic materials. Acoustic leakages commonly occur in actual vehicle conditions at pass-throughs or fastener mounting locations. The study also presents in-vehicle test results to demonstrate the effectiveness of the dissipative material in managing acoustic leakage.

Yoo, Taewook, Maeda, Hirotsugu, Sawamoto, Keisuke, Anderson, Brian, Gan, KimTong, Herdtle, Thomas

Evaluation of Material Damping Ratio of 2-Wheeler Electronic Ignition Switch Module to Enhance its Finite Element Model Physics for Harmonic Response

2025-01-0109

05/05/2025

The proposed work performs the detailed investigation of material damping ratio for different Electronic Ignition Switch Module (EISM) used in two-wheeler automobiles. A Finite Element Method (FEM) based simulation model has been developed. The simulation is performed by matching the failure areas of critical components in the assembly with physical sinusoidal vibration based shaker table test. The results (particularly breakage) have been reproduced by utilizing different damping ratios for the assembly. The damping ratio parameter is further utilized to perform FEM based harmonic response analysis for different EISM and evaluate critical structural breakage zones. The breakage zones predicted by simulation are found to be aligned with breakage zones depicted by shaker table sinusoidal test results. The simulation outcomes are validated, specifically considering the damping ratio parameter. The FEM based harmonic response analysis has been performed for a particular acceleration

Shah, Viren, Kalurkar, Shantanu, Kumar, Rahul, Kushari, Subrata, Miraje, Jitendra, D, Suresh, Parandkar, Parag

Leveraging Vision Language Models and Prompt Engineering for Bearing Defect Classification from Vibration Signals

2025-01-0127

05/05/2025

Bearings are fundamental components in automotive systems, ensuring smooth operation, efficiency, and longevity. They are widely used in various automotive systems such as wheel hubs, transmissions, engines, steering systems etc. Early detection of bearing defects during End-of-Line (EOL) testing and operational phases is crucial for preventive maintenance, thereby preventing system malfunctions. In the era of Industry 4.0, vibrational, accelerometer, and other IoT sensors are actively engaged in capturing performance data and identifying defects. These sensors generate vast amounts of data, enabling the development of advanced data-driven applications and leveraging deep learning models. While deep learning approaches have shown promising results in bearing fault diagnosis, they often require extensive data, complex model architectures, and specialized hardware. This study proposes a novel method leveraging the capabilities of Vision Language Models (VLMs) and Large Language Models

Chandrasekaran, Balaji, Cury, Rudoniel

Noise Analysis and Optimization of Thermal Management Integrated Module

2025-01-0081

05/05/2025

Thermal Management Integration Module (TMIM), which comprises components such as water pumps, runner boards, brackets, sensors, etc., is a multifunctional integrated component for electric vehicles. However, the water pump generates an excitation over a wide range of frequencies due to a wide range of speed variations. This excitation causes the TMIM to vibrate and generate noise. In this study, a TMIM that generates noise is studied and analyzed. Using the TMIM of an electric vehicle as a case study, a full-vehicle experimental test was conducted, revealing that the noise originates from the integration module. The finite element method is used to analyze the cause of noise generation. Given the characteristics of the TMIM, which comprise many components, high integration, and a complex structure, this paper simplifies the bracket, heat exchanger, sensor, and other components using the centralized mass point method. The modal state of the TMIM is obtained by impact hammer testing the

Xu, Shenao

Electric Bus NVH Challenges and Refinement Using Innovative Approach

2025-01-0080

05/05/2025

The trend towards electrification propulsion in the automotive industry is highly in demand due to zero-emission and becoming more significant across the world. Battery electric vehicles have lower overall noise as compared to conventional I.C Engine counterparts due to the absence of engine combustion and mechanical noise. However, other narrowband and tonal noises are becoming dominant and are strongly perceived inside the cabin. With the ongoing push towards electrification, there is likely to be increased focus on the noise impact of gearing required for the transmission of power from the electric motor to the road. Direct coupling of E-motors with Axle has resulted in severe tonal noises from the driveline due to instant e-motor torque ramp up from 0 rpm and reverse torque on driving axle during regenerative braking. The tonal noises from the rear axle during vehicle running become very critical for customer perception. For automotive NVH engineers, it has become a challenge to

Doshi, Sohin, Kalsule, Dhanaji, Sawangikar, Pradeep, Suresh, Vineeth, Sharma, Manish

A Comparative Analysis of Fault Diagnosis by Vibration Signals for Critical Gear Components in Electric Vehicle Motor Testing Machines Using Machine Learning Algorithms

2025-01-0040

05/05/2025

Electric vehicles (EVs) are shaping the future of mobility, with drive motors serving as a cornerstone of their efficiency and performance. Motor testing machines are essential for verifying the functionality of EV motors; however, flaws in testing equipment, such as gear-related issues, frequently cause operational challenges. This study focuses on improving motor testing processes by leveraging machine learning and vibration signal analysis for early detection of gear faults. Through statistical feature extraction and the application of classifiers like Wide Naive Bayes and Coarse Tree, the collected vibration signals were categorized as normal or faulty under both loaded (0.275 kW) and no-load conditions. A performance comparison demonstrated the superior accuracy of the wide neural networks algorithm, achieving 95.3%. This methodology provides an intelligent, preventive maintenance solution, significantly enhancing the reliability of motor testing benches.

S, Ravikumar, Sharik, N, Syed, Shaul, V, Muralidharan, D, Pradeep Kumar

A Theoretical and Experimental Investigation of NVH of In-Wheel Reducer and Motor Drive System

2025-01-0006

05/05/2025

To enhance the power density of the system and reduce production costs, the high-speed electric drive system featuring integrated design and control is poised to be the future development trend. However, the high speeds of motors and gear reducers can lead to challenges such as system reliability and issues related to NVH. This paper specifically addresses the NVH concerns associated with the in-wheel reducer and motor drive system (IWRMDS). First, a bench test scheme is established, and vibration and noise tests are conducted under a range of conventional operating conditions. The results indicate that at a torque of 200 Nm and a speed of 5500 rpm, the noise sound pressure level reaches 86.2 dB, highlighting significant vibration and noise issues within the system. Subsequently, Operational Deflection Shape (ODS) testing and analysis are performed on the system. It was discovered that the IWRMDS exhibits a relatively rich modal frequency spectrum, with the breathing mode being the

Huang, Chao, Xiong, Lu, Meng, Dejian, Gong, Yu, Guo, Han, Zhang, Mengyuan

Study on the Aspiration Properties of Glassrun Seal System under Time-Varying Pressure Difference

2025-01-0030

05/05/2025

When a vehicle is driven at high speed, there exists intricate flow pattern and vortex shedding at the side window area with intense pressure fluctuation. A significant dynamic pressure difference between the vehicle's exterior and interior can render the side window sealing system vulnerable to aspiration. This susceptibility can lead to the generation of leakage noise, adversely affecting acoustic comfort in the vehicle's cabin. This paper delves into the aspiration properties of glassrun seal system under time-varying pressure difference. A nonlinear finite element model of the glassrun seal was established to simulate the quasi-static deformation of the sealing strip during installation process, which aims to obtain the deformed geometric shape and residual stress after this process. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of

Li, Hanqi, He, Yinzhi, Zhang, Lijun, Zhang, Yongfeng, Yu, Wuzhou, Jiang, Zaixiu, Blumrich, Reinhard, Wiedemann, Jochen

Methodology for Sound Quality Metric Development

2025-01-0070

05/05/2025

While many individual technical descriptors exist to quantify and describe different kinds of acoustic phenomena, they each only describe the technical aspects of a sound itself without considering any additional non-acoustic context. Human perception, however, is greatly informed by this context. For example, humans have different expectations for the sound of an electric razor than they do for an internal combustion engine, despite both objects being able to be described by sound pressure level or a measure of roughness. No single technical descriptor alone works in all contexts as a gold standard which objectively determines whether a sound is “good.” Jury tests, however, are a great aid towards gaining a measure of this context. When seeking to effectively quantify the sound quality of a device, it is necessary to combine the perceptive information from the results of a jury test alongside one or more technical descriptors in order to provide a meaningful method of evaluation. The

Thiede, Shane

Experimental Characterization of a Steel Spring Mount Using Virtual Point Transformation

2025-01-0046

05/05/2025

The application of virtual point transformation for determining the transfer dynamic stiffness of a helical coil spring is demonstrated in this experimental study. Rigid fixtures are attached to both ends of the spring, and frequency response functions are measured using impact hammer excitations. These frequency response functions are transformed into virtual points, analogous to a node in finite element analysis, with six degrees of freedom. The six degrees of freedom transfer dynamic stiffness is then extracted using the inverse substructuring method, which eliminates the need to account for fixture dynamics. The results are validated by a direct measurement approach. Additionally, the study investigates the effect of liquid applied sprayed damping coatings on the spring's transfer dynamic stiffness, revealing that the coating significantly reduces vibration amplitudes at the surge frequencies. This suggest that the springs effective damping properties are enhanced.

Neihguk, David, Herrin, D. W., de Klerk, Dennis

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