This paper describes a three-dimensional structure of an adjustable field magnetization permanent magnet (PM) motor and a high-power density rotor structure with asymmetric permanent magnet arrangement for both high torque and high efficiency operation in the high speed and low torque range. 3D-FEA has confirmed that it is possible to achieve both high torque density and adjustable field magnetization. Load testing using the prototype proposed motor confirmed that high motor efficiency can be achieved even during high-speed operation.

Hiyoshi, Yutaro, Doi, Kotaro, Noguchi, Toshihiko

Analysis of the Effect of Combination Frame Flexibility on Weave Modes

2024-32-0049

To be published on 04/18/2025

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

Haraoka, Reiya, Katayama, Tsuyoshi, Yoshino, Takahiko

Development of Higher Clarity Injection Molded Windscreen for Motorcycles

2024-32-0040

To be published on 04/18/2025

The windscreen is one of the key elements to enhance passenger comfort of touring motorcycle. The clarity through the windscreen should not discomfort the rider. The discomfort we discuss here mainly refers to three factors: the “distortion,” the “blur,” and the “transparency.” Introduced in this paper is the technical measures to achieve sufficient clarity by the injection molding method. Firstly, with respect to the “distortion,” we determined the main cause was local unevenness of plate thickness. As the uneven thickness were related to the accuracy of the die, we clarified the tolerable zone and carried out higher precision machining of the die to satisfy the requirements. Regarding the “blur,” we analyzed the refractive power of the windscreen and found the main cause of blur is the microscopic roughness on the surface. As the microscopic roughness were attributable to the die surface, we clarified the tolerable zone and established the polishing conditions satisfactory for the

Yamada, Atsushi, Endo, Sakae

Prediction Method of Strength Robustness Affected by Arc Welding Sectional Dimensions

2024-32-0038

To be published on 04/18/2025

The arc welding process is essential for motorcycle frames, which are difficult to form in one piece because of their complex shapes, because a single frame has dozens of joints. Many of the damaged parts of the frames under development are from welds. Predicting the strength of welds with high reliability is important to ensure that development proceeds without any rework. In developing frames, CAE is utilized to build up strength before prototyping. Detailed weld shapes are not applicable to FE models of frames because weld shapes vary widely depending on welding conditions. Even if CAE is performed on such an FE model and the evaluation criteria are satisfied, the model may fail in the actual vehicle, possibly due to the difference between CAE and actual weld bead geometry. Therefore, we decided to study the extent to which the stresses in the joint vary with the variation of the weld bead geometry. Morphing, a FE modeling method and design of experiment method, was utilized to

Hada, Yusuke, Sugita, Hisayuki

Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism

2024-32-0013

To be published on 04/18/2025

In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn

Haraguchi, Tetsunori, Kaneko, Tetsuya

Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces

2024-32-0046

To be published on 04/18/2025

The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on

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

On the Application of Trapped Vortices in Motorsport Application for Improved Aerodynamic Performance Using Passive and Active Flow Controls

2025-01-5029

To be published on 04/15/2025

New regulations introduced by the Fédération Internationale de l’Automobile (FIA) for the 2026 Formula 1 season mark the first instance of active flow control methods being endorsed in Formula 1 competition. While active methods have demonstrated significant success in airfoil development, their broader application to grounded vehicle aerodynamics remains unexplored. This research investigates the effectiveness of trapped vortex cavity (TVC) technology in both active and passive flow controls, applied to a NACA0012 airfoil and an inverted three-element airfoil from a Formula 1 model. The investigation is conducted using numerical methods to evaluate the aerodynamic performance and potential of TVC in this paper. In the single-airfoil case, a circular cavity is placed along the trailing edge (TE) on the suction surface; for the three-element airfoils, the cavity is positioned on each airfoil to determine the optimum location. The results show that the presence of a cavity, particularly

Ng, Ming Kin, Teschner, Tom-Robin

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

09-13-02-0007

04/09/2025

The New Car Assessment Program (e.g., US NCAP and EuroNCAP) frontal crash tests are an essential part of vehicle safety evaluations, which are mandatory for the certification of civil means of transport prior to normal road exploitation. The presented research is focused on the behavior of a tubular low-entry bus frame during a frontal impact test at speeds of 32 and 56 km/h, perpendicular to a rigid wall surface. The deformation zones in the bus front and roof parts were estimated using Ansys LS-DYNA and considered such factors as the additional mass (1630 kg) of electric batteries following the replacement of a diesel engine with an electric one. This caused stabilization of the electric bus body along the transverse axis, with deviations decreased by 19.9%. Speed drop from 56 to 32 km/h showed a reduction of the front window sill deformations from 172 to 132 mm, and provided a twofold margin (159.4 m/s2) according to the 30g ThAC criterion of R80. This leads to the conclusion about

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

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

02-18-03-0014

04/09/2025

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

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

Effect of Catalyst Coating Strategy on NOx Reduction and Passive Soot Oxidation for Selective Catalytic Oxidation-Selective Catalytic Reduction Catalyst on Diesel Particulate Filter

2025-01-8490

04/01/2025

Selective catalytic oxidation/reduction catalysts coated on diesel particulate filters (SDPF) are an important technology route to meet next-stage emission regulations. The previous research of the research group showed that compared with SDPF coated with Cu-SSZ-13, the SDPF coated with novel selective catalytic oxidation-selective catalytic reduction (SCO-SCR) catalyst, which combined MnO2-CeO2/Al2O3 and Cu-SSZ-13, can simultaneously improve NOx reduction and soot oxidation performance. Catalyst coating strategy is an important parameter affecting the performance of SDPF. In this study, the effects of different coating strategies of SCO-SCR catalysts (C25, C50, C75, and C100) on the performance of NOx reduction and soot oxidation in SDPF were investigated. The results show that, as the inlet gas temperature increases, NO emissions first decrease and then increase, NOx conversion efficiency first increases and then decreases, and the rich-NO2 area, NH3 oxidation rate, N2O, CO, CO2

Chen, Ying-jie, Tan, Piqiang, Yao, Chaojie, Lou, Diming, Hu, Zhiyuan, Yang, Wenming

Adapting the Technology Readiness Level (TRL) Framework to Automated Vehicle Development

2025-01-8671

04/01/2025

Abstract The technological advancements in the automotive industry have seen a significant leap with the introduction of automated driving system (ADS)-equipped Vehicles (AVs), with potential for enhanced safety, efficiency, and mobility. 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 stage 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. The claim that the AV is ready to transition from one

Swaminathan, Sunder, Wishart, Jeffrey, Zhao, Junfeng, Russo, Brendan, Rahimi, Shujauddin

Integrated Bracket Design Optimizations to Resolve Issues in Vehicle Prototype Stage

2025-01-8614

04/01/2025

The integrated bracket is a plastic part that packages functional components such as the ADAS (Advanced Driver Assistance System) camera, rain light sensor, and the mounting provisions of the auto-dimming IRVM (Inner Rear View Mirror). This part is fixed on the windshield of an automobile using double-sided adhesive tapes and glue. ADAS, rain light sensors, and auto-dimming IRVM play an important part in the safety of the driver and everyone present in the automobile. This makes proper functioning of the integrated bracket very integral to occupant safety. Prior to this work, the following literature; Integrated Bracket for Rain Light Sensor/ADAS/Auto-Dimming IRVM with provision of mounting for Aesthetic Cover [1] outlines the design considerations and advantages of mounting several components on the same bracket. It follows the theme where the authors first define the components packaged on the integrated bracket and then the advantages of packaging multiple components on a single

Chandravanshi, Priyansh, Dharmatti, Girish

Efficient Simulation of Multi-Body Dynamics with Roller Guide Joints Using Julia

2025-01-8285

04/01/2025

Nonlinearities in mechanical systems pose significant challenges for efficiently solving multi-body dynamics (MBD) problems. Although simulations of traditional mechanisms with perfect joints can be performed efficiently, joints in practical applications are often characterized by clearances, leading to reduced simulation efficiency and accuracy. Improving solver effectiveness is essential for simulating systems with nonlinearities. This paper explores the use of Julia, a high-performance open-source programming language, to solve MBD problems formulated as index-1 differential-algebraic equations (DAEs). Euler parameters (quaternions) are employed to represent the orientation of rigid bodies. To illustrate the method's adaptability in addressing non-standard joint types, both perfect and imperfect (with clearance or friction) planar roller guide joints are modeled alongside common perfect joints. A case study of a vehicle sliding door system is presented. The numerical results are

Tong, Jiachi, Meng, Dejian, Lian, Yubo, Gao, Yunkai, Yang, James

A Methodology for Minimizing Liftgate-Induced Low-Frequency Boom Noise in Vehicles

2025-01-8617

04/01/2025

The significance of the liftgate's role in vehicle low-frequency boom noise is highlighted by its modal coupling with the vehicle's acoustic cavity modes. The liftgate's acoustic sensitivity and susceptibility to vehicle vibration excitation are major contributors to this phenomenon. This paper presents a CAE (Computer-Aided Engineering) methodology for designing vehicle liftgates to reduce boom risk. Empirical test data commonly show a correlation between high levels of liftgate vibration response to vehicle excitations and elevated boom risk in the vehicle cabin. However, exceptions to this trend exist; some vehicles exhibit low boom risk despite high vibration responses, while others show high boom risk despite low vibration responses. These discrepancies indicate that liftgate vibratory response alone is not a definitive measure of boom risk. Nonetheless, evidence shows that establishing a vibration level control guideline during the design stage results in lower boom risk. The

Abbas, Ahmad, Haider, Syed

A Survey of Vehicle Forward Lighting System Mounting Height and Driver Eye Height

2025-01-8662

04/01/2025

Headlight glare remains a persistent problem to the U.S. driving public. Over the past 30 years, vehicle forward lighting and signaling 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 and signaling equipment on vehicles from one or two decades ago are unlikely to represent the characteristics of current 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 and signaling 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

Bullough, John D.

Structural Seam Weld Optimization with Efficient Approach of DFSS

2025-01-8248

04/01/2025

In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout

Qin, Wenxin (Daniel)

Study on Relative Displacement in Assembly Structure Sections for Pre-Validation of Door Trim Noise

2025-01-8618

04/01/2025

The pre-validation process for door trim noise has gained increasing importance as noise standards have become more stringent with the transition to electric vehicles. Currently, the validation process employs squeak and rattle director simulations to evaluate noise based on relative displacement values. However, this approach is time-intensive. To address this limitation, we have improved process efficiency by developing a database of relative displacement values derived from the cross-sectional and structural characteristics of matching parts. This advancement enables noise pre-validation using only cross-sectional and structural information.

Cho, Wonhyung, Na, Hyunghyun, Kim, Donghyeon, Kim, JongSoo, Shin, Dongwan

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

2025-01-8079

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

Validation of SynthEyes for Use in Collision Reconstruction

2025-01-8688

04/01/2025

Accurate reconstruction of vehicle collisions is essential 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 and reduces the ability to determine moments of acceleration or deceleration. A more detailed speed profile can be calculated by solving for the vehicle’s position in each video frame; however, this method is time-consuming and can introduce spatial and temporal error 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 reconstructionists for determining vehicle speed from video. This study examines the

Perera, Nishan, Griffiths, Harrison, Prentice, Greg

Simulation and Parameter Optimization of Commercial Vehicle Cab Suspension System

2025-01-8268

04/01/2025

Taking a commercial vehicle cab suspension system as the research focus, a rigid-flexible coupled dynamics model was established based on the nonlinear characteristics of the integrated damper air spring and bushings. Time-domain vibration acceleration signals were acquired at the connection points between the frame, cab, and suspension. The vibration signals at the frame and suspension connection points were input into the simulation model, where the vibration responses at the cab and suspension connection points were calculated and analyzed using the established cab suspension system model. The accuracy of the model was verified by comparing the simulation results with experimental data. The established cab suspension system model was further used to evaluate human vibration comfort within the cab, following national standards for subjective human perception. A piecewise polynomial function was employed to fit the stiffness-damping characteristics of the integrated damper air spring

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

Regression Model based Method for Stiffness Design of Laminated Glasses

2025-01-8320

04/01/2025

This paper presents a new regression model-based method for accurate predictions of stiffness of different glass laminate constructions with a point-load bending test setup. Numerical FEA models have been developed and validated with experimental data, then used to provide training data required for the statistical model. The multi-variable regression method considered six input variables of total glass thickness, thickness ratio of glass plies as well as high-order terms. Highly asymmetrical, hybrid laminates combining a relatively thick soda-lime glass (SLG) ply joined with a relatively thin Corning® Gorilla® Glass (GG) ply were analyzed and compared to standard symmetrical SLG-SLG constructions or a monolithic SLG with the same total glass thickness. Both stiffness of the asymmetrical laminates and the improvement percentage over the standard symmetrical design can be predicted through the model with high precision.

Yu, Chao, Cleary, Thomas, Joubaud, Laurent, kister, Evan, Fisher, W Keith

Study on the Improvement of Pedestrian and Vehicle Visibility by Geometric Patterns Projection Lighting

2025-01-8663

04/01/2025

The proportion of pedestrian fatalities due to traffic accidents is higher at night than during the day. Drivers can more easily recognize pedestrians by setting their headlights to high beam, but use of high beam poses the issue of increasing glare for pedestrians. This study proposes a lighting technology that increases the noticeability of pedestrians for drivers and the noticeability of approaching vehicles for pedestrians while at the same time helping to reduce glare for pedestrians. The newly designed lighting enables geometric patterns projection lighting that makes use of projection technology. This geometric pattern projection lighting was compared with conventional low beam and high beam headlights to verify the effectiveness. Tests were conducted on a closed course with the participation of 20 drivers to evaluate the functionality of each headlight type. In these tests, subjects performed specific tasks such as evaluation of pedestrian visibility from the driver’s point of

Kawamura, Kazuyuki, Oshida, Kei

Drop Test Correlation in Front & Rear Landing Scenario for Two-Wheeler (Motorcycle) using Multibody Simulation

2025-01-8638

04/01/2025

Two wheelers motorcycles are used for many purposes e.g. commuting from one place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require higher suspension strokes to absorb large oscillations due to terrain conditions. These motorcycles undergo jumps of varying heights and different vehicle orientations. In some of the dynamic situations front wheel may land on the ground before the rear and in other cases it may be vice versa. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed in test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same test 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. Accelerations at

Jain, Arvind Kumar, Nirala, Deepak

Barrier Weight Prediction for Vehicle Compatibility in North America Market Using Finite Element Analysis

2025-01-8621

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 assembly of the larger high-voltage (HV) batteries. To comply with this weight increase and to meet stringent US regulations and Consumer Ratings requirements, Vehicle front-end rigidity (stiffness) has increased substantially. 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 to consider adopting a vehicle compatibility test like Euro NCAP MPDB (European New Car Assessment Program Moving Progressive Deformable Barrier) for the 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 Euro NCAP MPDB (European New Car Assessment Program Moving Progressive Deformable Barrier) protocol referenced for this analysis. Our evaluation

Kusnoorkar, Harsha, Koraddi, Basavaraj, Guerrero, Michael, Sripada, Venu Vinod, Tangirala, Ravi

A Study on Reconstructing in-Cylinder Combustion Images Based on Local Images

2025-01-8381

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

Investigation of Skin Friction Topology on the AeroSUV Using GLOF Meter

2025-01-8782

04/01/2025

In this study, the aerodynamics and surface flow field of a 1/5 scale SUV vehicle model called “AeroSUV” were experimentally investigated. The aerodynamics and surface flow field investigations were carried out in the wind tunnel at Hiroshima University with a Reynolds number ReL = 1.2×106, 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 surface 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 surface 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

Hijikuro, Masato, Shimizu, Keigo, Nakashima, Takuji, Hiraoka, Takenori

Propulsion System Design of Cadillac Lyriq Electric Vehicle

2025-01-8566

04/01/2025

The propulsion system design of GM-Cadillac’s first electric vehicle Lyriq uses an optimized drive unit comprising interior permanent magnet (IPM) motors and silicon traction inverters. The main objective behind the drive unit design was to minimize energy losses and cost while maximizing hardware consolidation, range, performance, power density, and scalability. Two IPM motors with different length and number of stator turns are designed, while their rotor design and stator-conductor profile are kept the same. A high-speed rotor is designed to achieve higher power density. AC winding effect at higher speeds is mitigated by using a bar-conductor with much smaller cross section. The rotor surface has a special notch design to minimize acoustic noise, without use of rotor or stator skew. Also, the traction inverters in the Lyriq EV are engineered with a significant emphasis on being scalable and adaptable for various vehicle architectures while considering a broad range of requirements.

Momen, Faizul, Jensen, William, He, Song, Chowdhury, Mazharul, Zahid, Ahsan, Forsyth, Alexander, Alam, Khorshed, Anwar, Mohammad, Kim, Young

A Modified Johnson-Cook Model Considering Strain-Temperature Coupling for Welding Simulation of Aluminum Alloy Bumper

2025-01-8243

04/01/2025

The metal inert-gas (MIG) welding technique employed for aluminum alloy automotive bumpers involve 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 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

Lattice Based Localized Energy Absorber for Improved Vulnerable Road User Performance for a Vehicle

2025-01-8723

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, such as hood stiffness and packaging space constraints, can lead to higher Head Injury Criteria (HIC15) 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 have limited energy absorbing capacity and tuning capability. This paper focuses on usage of a novel 3D printed energy absorbers, based on various kinds of lattice structures. These absorbers are either sandwiched between the inner and the outer

Kinila, Vivekananda, Agarwal, Varun, V S, Rajamanickam, Tripathy, Biswajit, Gupta, Vishal

Research on the Boundary of Pedestrian Leg Impactor Test in Low-Speed Passive and Active Conditions

2025-01-8735

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

Effects of Aging on PVC-Based Instrument Panel Skin for Passenger Airbag Deployment Analysis

2025-01-8321

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 on 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

G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar

Research on the Thermal Performance of Thick Film Heater for Electric Vehicle Battery

2025-01-8154

04/01/2025

A specific thick film heater (TFH) for electric vehicles is investigaed in this study, and its three dimensional heat tansfer analysis model is estab-lished. The heat transfer and fluid performance of the TFH is analyzed using a computational fluid dynamics soft-ware. 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 temperatures and flow rates, and the influence of the fin spoiler structure on TFH heating efficiency and the heating board temperature is investigated. The result indicates that the spoiler structure has a large effect on the board heating temperature, but has little effect on the heating efficiency. An orthogonal experimental design method is used to optimize the design of the fins and water channels, and the purpose is to reduce the board heating temperature for preventing over burning. Under the 25°C inlet

Guan, Wenzhe, Guo, Yiming, Wu, Xiaoyong, Wang, Dongdong, Shangguan, Wen-Bin

Rough Road Vehicle Dynamics Analysis for Vehicle Vibration Assessment

2025-01-8306

04/01/2025

This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model including non-linear tuning elements and flexible vehicle body is simulated on ride roads. The goal of the simulation is acceleration responses at the passenger locations in frequency domain. Body interface loads are recovered from the vehicle dynamic simulations. Frequency response function (FRF) of the body structure is ready in a fashion that input forces are applied to all body interface locations to the suspension and powertrains. This will give acceleration response sensitivity of the body structure to each body interface. The sum of body interface loads multiplied by FRF at each interface produces acceleration responses in frequency domain. A mid-size sedan model was used to demonstrate the process. A full vehicle dynamics model using Ansys Motion was simulated on a virtual ride road at a constant speed. The body loads were recovered in time domain

Hong, Hyung-Joo, Maddula, Pavan Kumar, Jun, Hyochan

Automated Analysis and Cleaning of Manufacturing Data: The Power of Automation Playbooks

2025-01-8332

04/01/2025

High-efficiency manufacturing involves the transmission of copious amounts of data, exemplified both by trends in the automotive industry and advances in technology. In the automotive industry, products have been growing increasingly complex, owing to multiple SKUs, global supply chains and the involvement of many tier 2 / Just-In Time (JIT) suppliers. On top of that, recalls and incidents in recent years have made it important for OEMs to be able to track down affected vehicles based on their components. All of this has increased the need for OEMs to be able to collect and analyze component data. The advent of Industry 4.0 and IoT has provided manufacturing with the ability to efficiently collect and store large amounts of data, lining up with the needs of manufacturing-based industries. However, while the needs to collect data have been met, corporations now find themselves facing the need to make sense of the data to provide the insights they need, and the data is often unstructured

Jan, Jonathan, Preston, Joshua, Juncker, John

Integrated Body Structure to Accommodate Manual and Power Door Sunshade Variants in a Vehicle

2025-01-8616

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

Virtual Analysis of Sound Propagation for Automotive Industry

2025-01-8631

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. [7] 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

Establishment of Failure Simulation Models for Bonding of Carbon Fiber Laminated Skins and Cores in Monocoque Structures Based on Formula Student Racing Cars

2025-01-8006

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. In recent years, 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, significant stress at the adhesive layer between the skin and the core material at both ends of the laminate, often lead 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 Spreadsheet. Therefore, it is necessary to consider the influence of the bonding factor of toughened epoxy prepreg film on the mechanical properties of the laminated plate. This

Ning, Zicheng

Predicting Forming Limit of Hot Stamping Boron Steel Using a Modified Zener-Hollomon Parameter based Ductile Failure Criterion

2025-01-8225

04/01/2025

Combined with a modified Zener-Hollmon parameter, a recently proposed ductile failure criterion is further improved to predict the forming limit of boron steel at hot stamping temperatures. The ductile failure criterion takes into account the critical damage at localized necking or at fracture as a function of strain path and initial sheet thickness. The modified Zener-Hollomon parameter accounts for both effect of varying strain rate and temperature for Boron steel. Working FEM simulation, the capability of the ductile failure criterion is further demonstrated by predicting forming limit of a boron steel in an isothermal Nakajima dome test. Comparison shows the prediction matches quite well with the measurement.

Sheng, ZiQiang, Mallick, Pankaj

Investigation of Flow Structures in Different Body Types Contributing to Drag Change Due to Crosswind

2025-01-8767

04/01/2025

To reduce aerodynamic drag during real-world driving, it is essential to consider the effects of crosswinds. The yaw angle dependence of aerodynamic drag is known to vary based on the vehicle body type; however, there are limited studies on the physical mechanisms underlying this difference, particularly through detailed visualizations of the flow structure and its response to yaw angles. This study investigates the differences in flow structures between an SUV and a notchback to understand the mechanism responsible for the variation in yaw angle dependence of CD under quasi-steady yaw angle conditions. Numerical simulations and wind tunnel tests were conducted for both the SUV and the notchback at yaw angles of 0°, 2°, and 5°. Crossflow and total pressure were employed as indicators for visualizing the flow structure, with a focus on the wake behind the vehicle in the visualizations of the wind tunnel tests and simulations. Additionally, isosurfaces of the crossflow velocity magnitude

Nakata, Akihiro, Okamoto, Satoshi, Nishida, Shuhei, Morikawa, Yosuke, Nakashima, Takuji

The Aerodynamic Development of the Range Rover

2025-01-8781

04/01/2025

The current 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 under-floor 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 outgoing 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

Chaligné, Sébastien, Gaylard, Adrian Philip, Simmonds, Nicholas, Turner, Ross

Simulating the DrivAer Notchback Car Model using Wall-Function LES

2025-01-8777

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

Design and Evaluation of a Conceptual Zero-Emission Truck Model Considering Aerodynamic Efficiency

2025-01-8784

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

Integrated Design for Body in White Fabricated by Additive Manufacturing and its Mechanical Performance Analysis

2025-01-8613

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

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