Browse Topic: Materials

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Comparative Analysis of Flux Linkage Characterization Methods for Automotive Permanent Magnet Traction Motors: A Critical Review and Performance Evaluation Framework2026-01-0441To be published on 04/07/2026
Accurate flux linkage characterization is essential for the design, control, performance and efficiency optimization of permanent magnet (PM) traction motors in automotive applications. Precise knowledge of flux linkage across varying load, speed, and temperature conditions directly impacts torque production, field-weakening capability, overall drive system efficiency and torque security. This paper presents a critical review and classification of flux-linkage characterization methods, encompassing offline laboratory mapping, standstill signal injection, self-commissioning inverter-only routines, and online real-time estimation. Each method exhibits distinct trade-offs in terms of accuracy, robustness to inverter nonlinearities, temperature adaptability, cost, and scalability for production and in-vehicle use. With the increasing complexity of automotive traction systems, understanding these trade-offs is crucial for optimal motor design and control. To enable systematic comparison, a
Khan, Ahmad Arshan, Haddad, Reemon, Kim, Jay, Hermann, Justin, Mohamadian, Mustafa
Design and Simulation Analysis of an Integrated Honeycomb-filled Front Bumper for a Special Vehicle2026-01-0475To be published on 04/07/2026
In frontal collisions of automobiles, the bumper beam at the front of the vehicle plays a crucial role in absorbing energy and protecting the vehicle body during a collision. To enhance the collision resistance of a specific type of special vehicle with a non-load-bearing body structure, this paper focuses on this type of vehicle and conducts a study on the design and collision performance of an integrated vehicle front bumper-impact beam structure based on aluminum alloy additive manufacturing technology. A novel bumper structure is proposed, which integrates the front bumper and the front impact beam of the vehicle and is integrally formed using aluminum alloy additive manufacturing technology. This integrated structure is directly connected to the vehicle frame. Firstly, based on the appearance of the special vehicle body and the form of the front impact beam of traditional passenger vehicles, an integrated design of the vehicle front bumper-impact beam structure is carried out and
王, Xufan, Yuan, Liu-Kai, Zhang, Tangyun, Wang, Tao, Zhang, Ming, Wang, Liangmo
A System-Level Calibration Framework for Embedded Vision: Integration of Sensor, Firmware, and Software Enhancements2026-01-0013To be published on 04/07/2026
Embedded vision systems are essential for contemporary applications, including robotics, advanced driver assistance systems (ADAS), and intelligent surveillance; yet they frequently experience diminished image quality due to resource constraints, environmental variability, and inconsistent illumination conditions. Such degradations impact multiple visual attributes-sharpness, contrast, color accuracy, noise levels, and structural similarity-that are critical for reliable perception in safety- and performance-driven domains. This study introduces a comprehensive system-level calibration architecture that integrates three coordinated layers: sensor-level adjustment, firmware optimization, and adaptive software enhancements. At the sensor level, exposure control, gain tuning, and white balance adjustments mitigate luminance imbalance and color shifts under changing light conditions. Firmware optimization leverages image signal processor (ISP) parameters to reduce temporal and spatial
Indrakanti, Rama Kiran Kumar, Vishnoi, Nitin, Kamadi, Venkata
Advancing Sustainable Electric Vehicles: A Simulation-Driven Study on Rare Earth-Free Motors and Battery Technologies2026-01-0242To be published on 04/07/2026
As electric vehicles (EVs) become more popular, the growing dependence on rare earth materials in their motors and batteries has raised concerns about supply risks, environmental impact, and rising costs. Finding alternatives to these materials is essential to making EVs more sustainable and affordable for everyone. This study aims to explore new motor designs and battery chemistries that reduce or eliminate the use of rare earth elements. We will focus on promising options like induction and wound rotor motors, as well as ferrite and iron-nitride magnets that can replace traditional rare earth magnets in EVs. On the battery side, we will look at lithium-iron-phosphate (LFP) and sodium-ion batteries, which offer a safer and more cost-effective alternative while maintaining good performance. A big part of this work involves using advanced simulations to predict how these new materials and designs will perform. This lets us optimize the components before building physical prototypes
Saraswat, Shubham, Vishe, Prashant
Beyond PFAS: Unlocking the Potential of R290 and R744 for EV Efficiency2026-01-0127To be published on 04/07/2026
The anticipated PFAS ban in the US by 2029 has created a need to evaluate alternative refrigerant solutions for automotive thermal management systems. This work compares three candidates—Propane (R290), Carbon Dioxide (R744), and R1234yf—through system-level testing and demonstration projects. R1234yf remains the current industry baseline. Test results show that Propane (R290) delivers comparable efficiency while offering a significantly lower global warming potential. However, its flammability presents integration challenges, not present with R1234yf or R744. CO₂ (R744) demonstrated promising performance as well. In AVL’s Refrigerant Cooling Project, direct CO₂ cooling battery plate simplified the thermal system architecture and provided adequate cooling capacity during high charging loads. To address safety concerns with Propane, AVL developed mitigation measures including rapid leak detection, robust containment strategies, and optimized circuit layouts designed to reduce ignition
bires, Michael, Possegger, Jonathan
Advancing Safe Battery Design through Experimental Cell Characterization of Thermal, Electrical and Mechanical Properties2026-01-0408To be published on 04/07/2026
Lithium-ion batteries are critical to electric vehicles and grid-scale energy storage. Safe design of battery systems relies on accurate simulation of battery thermal runaway under electrical, thermal, and mechanical abuse. A predictive battery simulation requires the characterization of electrical, thermal, and mechanical properties of the battery at the full cell and cell-component levels. In this study, a commercial cell from an electric vehicle was disassembled, and testing was conducted to support both homogenized and detailed computational models. At the cell level, electrical properties were characterized using Hybrid Pulse Power Characterization (HPPC) testing to assess the cell power capability. Cell punch tests were conducted to characterize mechanical behavior under deformation. These tests were used to develop a multi-physics homogenized cell model. On the other hand, detailed cell modeling that includes different component layers could help users understand localized cell
Challa, Vidyu, Rostami-Angas, Masoud, kong, Kevin, Wang, Leyu, Reichert, Rudolf, Kan, Cing-Dao
Design development and optimization of hybrid cross car beam for performance2026-01-0513To be published on 04/07/2026
The cross-car beam (CCB) within the instrument panel (IP) is a multifunctional structural element that supports safety, vibration control and modular integration in automotive design. The reduction of mass without compromising structural integrity plays a vital role in this endeavor. This study presents the design and optimization of design intent model of magnesium beam to meet the performance requirements Vs study model of hybrid cross car beam using magnesium steering column bracket, steel and plastic material to achieve reduced mass and enhanced stiffness while meeting performance targets. Advanced Computer Aided Engineering (CAE) techniques were employed, including topology optimization, lattice optimization, bracket sensitivity studies as well as shape & gauge optimization. Performed benchmarking against industry models such as Tesla Model Y observed hybrid material with structural simplification. The final hybrid beam design demonstrated overall cost reduction, while satisfying
Didgur, Gulzarahmed, McAdams, Ian, Viswaraj, Obuliraj
Optimizing joint efficiency in stainless steel-aluminum alloy FSW joints through advanced parameter control2026-01-0228To be published on 04/07/2026
The present work investigates the friction stir welding (FSW) of dissimilar materials, specifically stainless steel 304 and aluminum alloy AA2024-T3, to analyze their tensile strength behavior. The significant challenges inherent in joining these materials, stemming from their vastly divergent thermal and mechanical properties, are addressed through a structured experimental and statistical methodology. The L18 Taguchi mixed orthogonal array was employed to systematically evaluate the influence of three critical process parameters: tool rotational speed, welding speed, and tool pin offset. Eighteen experimental trials were conducted using a butt joint configuration. The analysis identified tool rotational speed as the most influential parameter affecting the joint integrity. A combination of 450 rpm rotational speed, 20 mm/min welding speed, and a 1.5 mm pin offset toward the aluminum side yielded the optimum results, achieving a peak ultimate tensile strength (UTS) of 344.7 MPa and a
Mir, Fayaz Ahmad, Khan, Noor Zaman, Pali, Harveer Singh
A Helical Compression Spring Fracture under Impact Velocity in Pump Operation by Theoretical Study and FEA2026-01-0271To be published on 04/07/2026
Helical compression springs have been used widely in various industries from automotive, aerospace and heavy-duty industries to electronics and medical devices. In the automotive industry, they appear in many places such as suspension, valvetrain, etc., especially in the discharge check valve of Gasoline Direct Injection (GDI) pump, which is the subject of study due to a recent fracture in lab testing. A theoretical study is conducted first to establish equation governing spring dynamic motion under impact velocity, which can be in high magnitude with surging shock wave along spring axis. A new spring shock wave equation is developed for spring axial motion coupled with coil torsional effect. This newly derived shock wave equation has a broad term than the classic spring formula found in engineering book. In the paper, it proves that the classic spring shock wave equation is only a special case for the new general wave equation discovered. Also, a formula on spring shock wave
Pang, Michael L., GUNTURU, SRINU, Norkin, Eugene
On-Engine Measurement of Automotive Turbocharger Turbine Blade Vibration2026-01-0201To be published on 04/07/2026
Automotive turbochargers are designed to avoid resonance of the turbine blades and backwall, which can result in High Cycle Fatigue failures. Blade Tip Timing is a method of turbomachinery testing which utilizes fiber optic probes to measure turbine blade displacements in real time on turbochargers spinning at upwards of 150,000 RPM. Historically, Blade Tip Timing measurements of automotive turbochargers have been made under steady-state conditions using a Hot Gas Stand. General Motors conducted testing of a turbocharger on a running engine to capture realistic exhaust pressure dynamics. A reference turbocharger was measured on an engine testbed running a production calibration; the same turbocharger was then tested on a Hot Gas Stand to observe how the blade behavior differed. Blade displacements were found to be lower on engine, because the dynamics of engine pulsation reduced the in-phase work available to drive the turbine blades, resulting in lower blade stresses and an
SCHWARZ, JORDAN, Goodheart, Rachel, Tappert, Peter, DePaoli, Dominic, Longacre, Christian
Computational Modeling and Optimization of Shape Memory Polymer-Based Energy Absorbers2026-01-0573To be published on 04/07/2026
Shape memory polymers (SMPs) provide tunable thermomechanical properties and enable the design of recoverable crash structures for automotive applications. This paper introduces a computational framework for the design and optimization of SMP-based crash absorbers with periodic auxetic microstructures. A finite element (FE) model is developed and validated against experimental data reported in the literature. The model is used to simulate crushing and recovery behavior under different temperature conditions. A parametric study is performed by varying key microstructural features, including wall thickness, cell size, and cell shape. Structural performance is evaluated in terms of specific energy absorption (SEA), peak force, and recoverability under axial crush loading. To efficiently explore the high-dimensional design space, surrogate models based on machine learning are constructed, and multi-objective optimization is carried out to identify Pareto-optimal designs that balance
Zhu, Yingbo, Zhu, Feng, Deb, Anindya
Vehicle Health Monitoring and Failure Prognosis through Edge-Based Component Wear Tracking2026-01-0094To be published on 04/07/2026
Traditional vehicle maintenance has relied primarily on mileage-based schedules and periodic visual inspections, approaches that often fail to account for variations in driving conditions, component quality, and usage patterns. These conventional methods typically result in either unnecessary premature replacements or unexpected component failures, leading to increased operating costs and unplanned downtime. Reactive maintenance strategies prove particularly problematic for critical wear components like clutch assemblies, brake systems, and suspension parts where undetected degradation can cause secondary damage. This paper presents an advanced monitoring system that shifts from scheduled maintenance to actual condition-based servicing through real-time wear measurement. The solution implements a network of distributed sensors that directly track critical parameters: ultrasonic measurement of clutch plate thickness, resistive wear sensors for brake pads, linear potentiometers for
Saraswat, Shubham, Vishe, Prashant
CFD Modelling of Cell Formation Gas and Venting During the EV’s Battery Manufacturing Process2026-01-0384To be published on 04/07/2026
The electric battery is a critical component of electric vehicles (EVs), where high power demands pose significant operational challenges. One such challenge is gas generation within the porous anode layer, which can lead to pressure buildup inside the battery. The complex interfacial dynamics at the microscale play a crucial role in determining the effectiveness of gas venting and the resulting pressure evolution. This study addresses this issue through a two-pronged simulation approach. First, gas generation within a representative anode microstructure is investigated using a Volume of Fluid (VOF) framework that resolves tortuous flow passages. The simulations reveal that gas generation in such microstructures can lead to pressure rises of several thousand Pascals, with interfacial behavior primarily governed by surface tension effects. Second, a high-level battery pack simulation is performed using a porous media approach to evaluate system-scale gas venting and localized
Mahyawansi, Pratik J., Schlautman, Jeff, Viswanath, Priyanka, Srinivasan, Chiranth
Dynamic Characterization and Viscoelastic Modeling of Polymer Foams for Automotive Applications2026-01-0236To be published on 04/07/2026
Viscoelastic behavior of polymeric materials serves as a critical indicator of their internal structure and chemical composition, offering valuable insights into energy absorption and dissipation mechanisms. This study focuses on the dynamic characterization of polymer foams through both experimental and numerical approaches, aiming to accurately capture their time and frequency dependent mechanical response. Experimental investigations include uniaxial tension and uniaxial compression, which characterize hyperelastic or instantaneous behavior of the material. Stress relaxation tests and Dynamic Mechanical Analysis (DMA) characterize the dependence on time, frequency and temperature. A combination of these tests is effectively utilized to create viscoelastic material models that can describe the material response as a function of time, frequency and temperature containing a viscous and an elastic part. This paper presents dynamic characterization of polymer foams in finite element
M, Gokula Krishnan, Lin, Chunfu, Savic, Vesna
Impact of C-rates on Electrical Behavior of Li-ion Batteries under Coupled Temperature-load Conditions2026-01-0383To be published on 04/07/2026
The utilization of lithium-ion batteries in electric vehicles becomes increasingly common. Battery performance degradation is influenced by both temperature and boundary constraints. Monitoring the usable cell capacity (UCC) under real-world operating conditions is essential for ensuring accurate state-of-health estimation. Capacity tests in laboratory settings are typically conducted at low C-rates to approximate equilibrium conditions, whereas in real vehicle applications, charging currents are often much higher. This discrepancy in charge/discharge rates frequently results in deviations between laboratory characterization and on-board BMS capacity estimation. To investigate the impact of C-rates under coupled temperature-load conditions, we conducted long-term cycling tests on LFP/graphite pouch cells at 25 °C and 45 °C under different constrained conditions. The UCC was evaluated at different test rates (1/20C, 1/3C, and 1C) as an indicator of aging. The results show that
ZHANG, Shan, Niu, Zhice, Xia, Yong
Investigation on Microstructure and Mechanical Properties in the Dissimilar Joining of WE43 to AA7075 Alloy using FSW2026-01-0229To be published on 04/07/2026
This research investigates the alterations in microstructure, microhardness, and joint strength resulting from the dissimilar friction stir welding (FSW) of WE43 magnesium alloy to AA7075 aluminium alloy. The study specifically analyses the role of FSW process parameters in the formation of intermetallic compounds (IMCs), the evolution of grain structure, the resultant microhardness distribution across the weld zone, and the joint tensile strength. A comprehensive microstructural characterization was performed utilizing optical microscopy (OM), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDS), electron backscatter diffraction (EBSD), and X-ray diffraction (XRD). These analyses confirmed significant refinement of grain in the stir zone and the identification of various IMCs at the weld interface. Microhardness mapping indicated a gradient profile, with the weld nugget exhibiting superior hardness attributed to its dynamically
Ahmad, Tariq, Khan, Noor Zaman, Ahmad, Babar, Siddiquee, Arshad Noor
Adhesion Strength of Coatings in Battery Structural Joints2026-01-0238To be published on 04/07/2026
In the design of Rechargeable Energy Storage System (RESS) structures, including battery trays, module side plates, and end plates, there are multiple conflating factors, including: Mechanical requirements necessitating the use of electrically conductive materials (steel and aluminum); proximity between battery module structure and battery cells, necessitating the use of electrical isolation coatings; and module and pack designs that retain cells via the use of Structural Adhesive Material (SAM). Inherently, with this design approach, organic coatings are placed in a new and perilous position. In a sense, the coating becomes a supplement to an adhesive. As virtual analysis tools have become more sophisticated, there is increasing reliance on these tools to predict the occurrence of structural failures in various load cases. Factors in test method, paint pretreatment, and topcoat affecting adhesion of organic coatings in structural adhesive joints are discussed, including: Adhesive
Moceri, Charles, Harper, Jared
Protection of Megawatt-Scale DC Charging Infrastructure for Heavy Duty Vehicles: A Review of Current Technologies and Future Roadmap2026-01-0400To be published on 04/07/2026
Abstract Direct Current (DC) fast charging enables the direct delivery of megawatt (MW) scale power to the large battery systems of heavy-duty electric vehicles (EVs), such as trucks, buses, and construction machinery. This contrasts with Alternating Current (AC) charging, which is constrained by the limited capacity of onboard chargers. The feasibility of ultra-fast DC charging has been driven by advancements in semiconductor technology offering higher voltage and current handling capabilities as well as improvements in battery energy density. Ongoing research indicates continued growth in both semiconductor power handling and battery storage capacity, further strengthening the case for ultra-fast DC charging. Key benefits include significantly higher charging efficiency, drastically reduced charging times, and lower driver fatigue. However, unlike AC systems, DC charging infrastructure presents unique protection challenges. These challenges arise from the rapid rise of DC fault
Rahman, Md Rakib-Ur, Dobrzynski, Daniel
High Strain-Rate Behaviors of Fiber Reinforced Composites in Principal and Off-Axis Directions2026-01-0175To be published on 04/07/2026
Materials can exhibit significantly different mechanical behaviors compared to quasi-static conditions at high strain rates (> 100 s-1). High strain rate tests using setups such as SHPB (Split-Hopkinson Pressure Bar) can provide, in a practicable manner, the stress-strain relations for a material at high strain rates. Such properties are vitally needed for activities such as simulation-driven impact safety design of composite structures deployed in the form of automotive body parts and assembly, and other sub-systems. Although the behaviors of isotropic and ductile materials such as various metallic alloys appear to have been extensively studied and reported in literature, dependence of mechanical properties of fiber-reinforced composites especially in different off-axis directions are extremely difficult to come across. To fill up this void, a detailed experimental study has been carried out on high strain rate mechanical characterization of orthotropic glass, carbon and a natural
Bawa, Prashant, Deb, Anindya, Zhu, Feng
A novel chemical clustering approach for the acceleration of 3D CFD simulations of internal combustion engines with complex fuels2026-01-0495To be published on 04/07/2026
Accurate fuel chemistry modelling is critical for internal combustion engine (ICE) simulations, especially when assessing fuel composition effects, preferential evaporation, and emissions. This need grows with the increasing use of e-fuels and blends with conventional fuels. While detailed chemical kinetics offers high fidelity, computational cost often limits its practical application. This paper introduces an extended chemical kinetics clustering approach to accelerate complex fuel simulations in 3D CFD. Building on a previously published method, the approach targets multi-component fuels with strong local inhomogeneities. By grouping cells with similar thermochemical states during source term evaluation, redundant calculations are reduced. The method is robust for a wide range of fuels, from simple surrogates to complex gasoline blends. Benchmark results and an evaluation of the clustering strategy are presented for a direct injection gasoline engine. Simulations are performed using
Hernandez, Ignacio, Turquand d Auzay, Charles, Shapiro, Evgeniy, Shala, Mehmet, Borg, Anders, Seidel, Lars, MAUSS, Fabian, Brandes-Grote, Kerstin
Application of Fatigue Damage Criteria to CAE-Based Fatigue Life Prediction of a Welded Chassis Component2026-01-0232To be published on 04/07/2026
In recent years, computer-aided engineering (CAE) has become an essential practice in design and durability analysis of industrial components such as weldments. The current analytical trend for CAE-based fatigue life prediction of weldments includes procedures based on design guidelines, mesh-sensitive methods (e.g., local strain-life approach) and mesh insensitive methods (e.g., Volvo and Verity methods). As an inherent characteristic of weldments, the geometry of the weld is often simplified in failure analysis and important hotspots such as start/stop of the weld beads are not considered in designing process. However, such critical locations cannot be avoided in complex welded structures. Therefore, incorporating main geometrical details of the weld can improve the accuracy of critical regions identification and damage calculation using mesh-sensitive CAE-based methodologies. Herein, a framework for life prediction of welded components including the weld geometry is discussed and
Razi, Ahmad, Kim, Dooyoung, PARK, Jaehong, YOUK, Wansoo, Fatemi, Ali
Impact of Core Glue Coverage and Stacking Factor on Glue-laminated Motor Material Properties and Its NVH Behavior2026-01-0439To be published on 04/07/2026
The influence of core glue coverage and stacking factors on the mechanical properties of core material is investigated in this study. As these structural attributes of the motor directly affect the mechanical behavior of the e-drive system, such as the NVH and durability performance, their influence on NVH is also analyzed under electromagnetic loads. With the unit-cell method previously proposed for predicting laminated motor core material properties, the material used in the finite element analysis (FEA) model for the glue-laminated motor core is homogenized over the laminations and idealized macroscopically as a transversely isotropic material. A numerical FEA method to quantify the effect of the glue coverage rate and stacking factor in a statistical or averaged sense to establish their relationship with the linear transversely isotropic properties. The glue is assumed to be evenly distributed over the lamination plane, and changes in the in-plane and out-of-plane elastic modulus
Nie, Zifeng
Thermal Insulation Materials Used in Battery Pack Assembly: A Review of Materials, Test Methods, and Key Considerations2026-01-0406To be published on 04/07/2026
Electric vehicle (EV) battery packs have undergone substantial advancements in recent years, driven by engineering design improvements, material innovations, and increasingly stringent regulatory enforcement. These developments have enabled battery packs to become more energy-dense, which is essential for extending driving range and improving overall vehicle performance. However, with increased energy density comes a heightened risk of thermal events, such as thermal runaway, which continue to raise concerns regarding vehicle safety, reliability, and long-term durability. This review focuses on the critical role that thermal insulation materials play in mitigating the impact of such thermal events within EV battery systems. It presents an overview of commonly used thermal insulation materials, emphasizing their chemical composition, thermal resistance, and mechanical integrity under extreme conditions such as high temperatures and physical stress. The ability of these materials to
Ng, Sze-Sze, Dhyani, Abhishek, Gorin, Craig, Jeon, Junho, Nuguri, Sravya, Repollet Pedrosa, Milton, Rylski, Adrian, Shete, Abhishek, Steinbrecher, Jacob, Thomas, Ryan
AI LabelMate: A Context-Aware Annotation Agent for Reducing Semantic Fragmentation2026-01-0261To be published on 04/07/2026
Robust perception systems for autonomous vehicles depend critically on high-quality labeled data, especially for off-road and unstructured environments. However, perception model performance is often degraded by 'data chaos' from limitations in automated segmentation. Foundation models like SAM2, while powerful, usually generate masks based on low-level visual cues like color and texture gradients. In complex off-road scenes, this leads to semantic fragmentation. A single object, like a moss-covered log, can be split into not only dozens of segments for its bark and moss, but also hundreds of smaller, meaningless patches based on minor color variations. This paper introduces a context-aware annotation agent to resolve this issue. Our workflow integrates a vision-language model (Florence-2) for scene understanding with a segmentation model (SAM2) for mask generation. Instead of segmenting indiscriminately, our agent leverages Florence-2 to comprehend the image holistically, localizing
Patil, Ashish, Mikulski, Dariusz, Mwakalonge, Judith, Jia, Yunyi
Research on the control of magnetic weakening scheme for the voltage utilization rate of hybrid transmission2026-01-0447To be published on 04/07/2026
This paper proposes a weak magnetic control method for PMSM current regulators based on the ratio of pressure to frequency and voltage utilization rate when the motor speed exceeds the weak magnetic speed. That is, the direct-axis offset current id is generated through the action of weak magnetic feedforward and weak magnetic I regulator, and the control of weak magnetic speed can directly adjust the demagnetization effect of id to achieve weak magnetic control of PMSM. The weak magnetic control method of PMSM current regulators with the outer loop of voltage utilization rate is adopted. It is proposed to use the phase-locked loop control method to decode the motor position signal in a closed loop and calculate the motor speed. The fluctuation of the position signal is reduced and the signal is more stable. This paper realizes constant power speed regulation based on high voltage utilization rate and weak magnetic control method at high speed operation above the base speed, which
Jing, Junchao, Yan, Xiaoqian, Liu, Yiqiang, Sun, Fengjiao, Dai, Zhengxing
Application of DFSS for Optimizing Thermal Protection in Electric Vehicles During Battery Thermal Runaway Events2026-01-0142To be published on 04/07/2026
Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics based transient heat transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L 18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant egress safety requirements. Findings confirm DFSS as an effective framework for developing high
El-Sharkawy, Alaa, Asar, Mona, Taha, Nahla, Sheta, Mai
Multi-material topology optimization using difference-based equivalent static load method2026-01-0173To be published on 04/07/2026
Topology optimization (TO) has become a powerful tool for generating lightweight structural designs. TO has been widely applied to linear static problems, where analytical sensitivities are easy to obtain. However, crashworthiness design requires nonlinear dynamic analysis, for which analytical sensitivities are generally not available. To extend TO into crash problems, approximation methods such as the Equivalent Static Load (ESL) method have been developed. ESL replaces the nonlinear problem with a series of linear static subproblems, ensuring that the displacement fields match at certain time steps. These subproblems can then be efficiently solved using standard TO techniques. A key limitation of ESL is that it relies on the initial mesh for all subproblems, which reduces accuracy for highly nonlinear crash responses. To address this, Triller proposed the difference-based ESL (DiESL) method, which updates the mesh in each subproblem to the deformed configuration, therefore improving
Huang, Yuhao, Kim, Il Yong
Data-Driven Objective Road-Driving Classification For Durable Design Of Vehicles2026-01-0181To be published on 04/07/2026
Durability development in the automotive industry depends on a clear understanding of how road surfaces and driving characteristics affect structural road loads and fatigue. Traditionally, road surface classification has been subjective (e.g., city, highway, rural), and done through driving instrumented vehicles over a small selection of roads. The variations in driving characteristics that are often consequent to the road surface quality is rarely accounted for in designing vehicle level durability tests. This makes it difficult to establish targets for the durability testing that accurately match the wide variations in real-world roads and driving across the market of vehicles. This paper presents a data-driven approach to objectively classify road surface and driving characteristics using metrics derived from existing vehicle and road response metrics like Vibration Dose Value (VDV), International Roughness Index (IRI) and statistical estimates of vehicle speed and acceleration
Shaurya, Shubham, Ramakrishnan, Sankaran, Demiri, Albion, Khapane, Prashant
A Study on Fatigue Life Prediction Method for Point-Based Joints Considering Multiple Fracture Modes – FDS, Blind Rivet, and Blind Nut Focus2026-01-0180To be published on 04/07/2026
The application of light weight alloys for vehicle bodies such as aluminum alloys and composite materials are rapidly advancing to support the construction of multi-material vehicle bodies. These materials play a crucial role in reducing overall vehicle weight, enhancing fuel efficiency, and complying with increasingly strict environmental regulations. As the automotive industry continues to evolve toward electrification and sustainability, the integration of lightweight and high-performance materials has become a key design strategy. However, the use of multiple materials introduces new challenges in manufacturing, particularly in joining technologies. Since different materials have varying mechanical properties, thermal behaviors, and surface characteristics, selecting appropriate joining methods is essential to ensure structural integrity and durability. Depending on the material types, thicknesses, production processes, and cost constraints, various joining techniques—such as
Takuno, Sougo, Isono, Toshiyuki, Urakawa, Kazushi, Goto, Suguru, Kawamura, Hiroaki, Niisato, Eita, Ishigami, Yuta
Optimizing Weld Placement in Automotive Structures Using Topology and Multi-Disciplinary Approaches2026-01-0514To be published on 04/07/2026
This work presents two approaches for weld optimization aimed at reducing manufacturing cost and process time, while meeting structural performance requirements in automotive structures. The first approach uses topology optimization to identify the most efficient weld layouts. A design space is generated along mating flanges, joints, and panel interfaces, where potential weld locations are defined. Welds are treated as discrete design variables, and the topology optimization systematically evaluates their contribution to global stiffness and load path integrity. Non-critical welds, those with minimal impact on stiffness, durability, or crashworthiness, are eliminated, resulting in a minimized weld pattern that maintains structural performance. The second approach applies Multi-Disciplinary Optimization (MDO) to balance weld reduction with performance targets across multiple domains, including linear and non-linear stiffness, crashworthiness, and fatigue. Using a preprocessing tool
Koppaka, Vinaya, Yoo, Dong Yeon, Chavare, Sudeep
Experimental investigation wear of the power cell assembly of an internal combustion engine operated with ethanol through vibration and oil analysis2026-01-0352To be published on 04/07/2026
The durability test is an experimental test widely used in the automotive industry to verify the ability of an engine to withstand all operating conditions throughout its useful life. The test is performed on a dynamometric bench that subjects the engine to specific operating cycles. The objective of this study was to monitoring the level of wear of the power cell assembly and the performance of the engine operated with ethanol during the durability test. Wear monitoring was performed through the application of vibration analysis and lubricating oil analysis techniques. The results showed that the level of wear and performance of the engine after the durability test were considered satisfactory. Compared to durability tests previously conducted without monitoring, the analysis of wear metals in the lubricating oil and oil properties, combined with vibration analysis throughout the durability test, allowed for safe testing with a shorter total test time, optimized technical downtime and
Santana, Claudio Marcio
Understanding the Effects of Process Parameters on the Dispense Uniformity of Elastomeric Silicone Coating Material for Automotive Manufacturing.2026-01-0239To be published on 04/07/2026
As electric vehicle (EV) manufacturing scales, innovative approaches have been evolving for battery fire protection materials to mitigate thermal runaway hazards, including fire and blast protective coatings. These materials often exhibit high-viscosity and must be deposited with uniform thickness and stable geometry to ensure reliable thermal barriers and battery pack integration. In practice, coating uniformity (uniform thickness, edge fidelity, and minimal sag/run prior to cure) is highly sensitive to dispense conditions, including nozzle slot width, nozzle length, effective dispense height (stand‑off), nozzle sweep speed, and volumetric dispense rate. Establishing robust process understanding early is therefore essential to avoid start‑up scrap, rework, and variability downstream. This paper presents a combined computational and experimental methodology to optimize and de‑risk dispensing of elastomeric battery fire protection (BFP) coatings. We develop a physics‑informed modeling
Hossain, Arif, Repollet Pedrosa, Milton H., Norquest, Kade, Mcmichael, Jonathan, Ng, Sze-Sze, Aradhyula, Pranavi, Thomas, Ryan, Gorin, Craig, Dietsche, Laura, Kenney, James A.
Tensile and Fatigue Behavior of High Pressure Die Cast AE44 Magnesium Alloy at Elevated Temperatures2026-01-0234To be published on 04/07/2026
Tensile and cyclic behavior of high pressure die cast AE44 magnesium alloy have been studied at room temperature and elevated temperatures up to 350°C. Anelastic behavior has been found in both tensile and cyclic deformation at the temperature below 150°C. With increasing temperature, the anelasticity disappears, and tensile and cyclic behaviors become similar to other engineering materials, such as steels and aluminum alloys, i.e. the total strain contains only elastic strain and plastic strain. A method to determine the yield strength at 0.2% plastic strain (σ0.2) is proposed. By using the proposed method, the yield strength σ0.2 is higher than that determined using the traditional method, which is more suitable to the materials that do not exhibit anelasticity. It is believed that the anelasticity is closely related to twinning in Mg alloy, which disappears at elevated temperatures.
Liu, Yi, Yang, Wenying, Coryell, Jason
Multi-Objective Topology Optimization for Cost and Time Minimization in Fiber Reinforced Additive Manufacturing2026-01-0257To be published on 04/07/2026
Fiber Reinforced Additive Manufacturing (FRAM) combines the geometric freedom of additive manufacturing with the high strength-to-weight ratio of composite materials, enabling the production of lightweight, high-performance automotive components. The anisotropic nature of fiber-reinforced composites makes their mechanical performance highly dependent on fiber orientation relative to applied loads. Leveraging this directional behavior through optimization provides opportunities to enhance structural efficiency while reducing vehicle weight. Conventional FRAM research has largely focused on structural objectives such as compliance minimization, often overlooking manufacturability challenges. In particular, support structures - temporary features required for overhang fabrication - can significantly increase print time, material usage, and production cost, limiting industrial adoption. To address this gap, this research introduces a novel multi-objective topology optimization framework
Wotten, Erik, Kim, Il Yong
Machine Learning Modeling for Compressive Property Prediction of Foams2026-01-0512To be published on 04/07/2026
Foam material models for automotive structural analysis typically require tensile and compressive data at multiple strain rates. The testing is costly and may require a long time to complete. For many applications, foams of similar chemistry are used and the foam structural responses, such as stiffness and compression force deflection, are controlled by the foam density. In such cases, Machine Learning (ML) lends itself as an ideal tool to detect the trends in material response based on density and strain rate. In this paper, five microcellular polyurethane (PU) foams of different densities were tested at four strain rates ranging from 0.01/s to 100/s. A ML model capable of predicting compressive stress-strain response for a range of densities was developed. The model demonstrated good prediction capability for intermediate strain rates at all foam densities and in extrapolating stress-strain curves at higher densities at all strain rates. The strain rate trends for a density outside
M, Gokula Krishnan, Kavimani, Harish, Muppana, Sai Siddhartha, Savic, Vesna, Chavare, Sudeep, V S, Rajamanickam
Analysis of Failure Causes and Optimisation of Automotive Cycloidal Rotor Pumps2026-01-0184To be published on 04/07/2026
Cycloidal rotor pumps are widely employed in automotive and aerospace industries due to their compact structure, high volumetric efficiency, and minimal flow pulsation. With the advancement of new energy vehicles, rotor pumps are increasingly required to operate reliably under more demanding conditions, including higher rotational speeds, elevated pressures, and more severe operating environments. These requirements place greater emphasis on pump durability and structural integrity. This study investigates a fracture failure of the internal rotor observed during bench testing of a cycloidal rotor pump. Metallographic and physicochemical analyses were conducted on the failed rotor. The results indicated that the fracture was not attributable to material defects. Instead, the failure originated from improperly designed slot locations within the rotor, which created a structural weak point at the slot opening. Additionally, sharp corners introduced during machining of the slots resulted
Li, Meng, Xie, JIa, Qin, Gongyu, Yang, Hanming, Wang, Liangmo
Anisotropic mechanical property simulation of fiber reinforced PEEK using composite theory and comparison to experimental results2026-01-0256To be published on 04/07/2026
The mechanical properties of 3D printed composites have been shown to vary due to the manufacturing infill direction due to artifacts from the printing process. PEEK (Polyether Ether Ketone) and PEEK reinforced with carbon fiber were studied for these experiments because they are widely used for their high strength properties. 3D printed composites that behave with anisotropic characteristics have been evaluated under Laminate Composite Theory (LCT), which can be used to determine the mechanical properties of these 3D printed composites. By changing the orientation of the extruded strands in a 3D printed part, the structure can be optimized in a specific orientation for specific loading conditions, and LCT can be applied for simulating mechanical responses. Three point bending tests were performed on rectangular 3D printed samples and compared to a 3D simulation using LCT for a similar bending load. This allows for the use of LCT in combination with a finite element software such as
Bradley, Coilin, Garcia, Jordan, Sibley, Brian
Lightweight Bubble Sheet Panel To Reduce Inverter Noise and Vibration for Electric Vehicles2026-01-0442To be published on 04/07/2026
Inverters are typically integrated into electric drive units for electric vehicles (EVs) to reduce packaging size and cost. However, coupled vibrations from the electric motor and gears are transmitted to the inverter, which, due to its large radiative panel, becomes a dominant noise source. Metal panels are required for electromagnetic interference (EMI) compliance, yet these covers usually lack sufficient stiffness or damping for noise control. Adding ribs and applying damping treatments results in excessive mass, cost, and packaging challenges. A new, patented bubble sheet panel design has been developed to enhance the structural strength and damping of the inverter while significantly reducing its mass. A thin sheet of aluminum or magnesium is welded onto the cover in an optimized pattern that enhances stiffness and damping performance while accommodating packaging requirements. The welding pattern can include logos or artistic designs to improve the panel’s appearance. The metal
He, Song, Bobel, Andrew, Naismith, Gregory, Yi, Wenwen, Patruni, Pavan Kumar
Effective Prediction of the Mechanical Properties of Glue-Laminated Motor Core with consideration of glue disposition and stacking factor.2026-01-0177To be published on 04/07/2026
This study presents a practical approach for predicting the mechanical properties of glue-laminated motor cores, with a particular focus on the influence of glue disposition patterns and coverage rate, to enable more accurate material modeling and reliable NVH and other general structural analysis. Since glue bonding and lamination stacking are essential for ensuring the structural integrity of motor stator cores, variations in glue implementation introduce significant changes in both in-plane and out-of-plane stiffness properties. To address this, a homogenization framework based on the unit-cell method, considering detailed glue application information, is employed. The laminated structure is idealized as an orthotropic material, and the variation of in-plane properties in different directions is considered. Unlike simplified coverage-rate models, the proposed method incorporates localized glue distribution patterns—such as teeth, core back iron, and edge-concentrated regions like
Nie, Zifeng
Development of an Advanced Tensile Testing Method for HDPE Composites in High Draw Molded Hollow Circular Regions: Effects of Sample Preparation, Asymmetry, Thermal Conditions, Pull Speed, and Fixture Parameters.2026-01-0204To be published on 04/07/2026
High-density polyethylene (HDPE) composites, particularly in high draw molded hollow circular configurations, present unique challenges in evaluating mechanical performance under tensile stress due to anisotropic deformation, geometric asymmetry, and localized thermal gradients. This study introduces an advanced tensile testing methodology designed specifically to assess such regions with greater precision and reproducibility. The method incorporates refined sample preparation protocols, tailored fixture geometry, and adjustable pull speeds to accommodate varying thermal histories and draw ratios inherent to molded sections. Systematic variation of asymmetrical, temperature conditions, and clamping techniques revealed significant impacts on tensile strength, elongation at break, and strain distribution. Findings emphasize the necessity of customized testing frameworks for molded composite geometries and demonstrate that fixture alignment and thermal conditioning are critical to
BHALERAO, SAURABH SHANKAR
A Novel Spot Joint Element for Fatigue Evaluation of Spot Welds and Fasteners in Lightweight Automotive Structures2026-01-0182To be published on 04/07/2026
Due to the spot weld and mechanical fastener share the similar characteristics to join sheets together with only differences in deformation behavior around joint region, a novel spot joint element (user-defined element) consists of regular Mindlin shell elements and equations for different kinematic constraints is proposed to simplify the spot joint representation in lightweight automotive structures. The novel spot joint element can not only provide accurate deformation behavior around joint region but also output mesh-insensitive structural stresses at virtual nodes with the use of traction-based structural stress method for fatigue failure analysis. In this investigation, the structural stress distributions around joint peripheral in the lap-shear specimens with spot weld or fastener are first calculated to validate the accuracy of the novel spot joint element. Then, the structural stresses along different cross-sections emanating from joint are also calculated for the specimens
Wu, Shengjia, Zhang, Lunyu, Dong, Pingsha
Optical investigation of Argon Power Cycle (APC)2026-01-0328To be published on 04/07/2026
The growing global demand for energy, combined with the urgent need to reduce greenhouse gas (GHG) emissions, is driving the development of alternative combustion technologies across transport sectors. Low- and zero-carbon fuels such as methanol, ammonia, and hydrogen are being explored as viable replacements for fossil fuels in internal combustion engine (ICE) applications. Among these, hydrogen stands out due to its wide flammability range and fast, carbon-free combustion. Research is ongoing to understand how hydrogen and other alternative fuels can be used most efficiently in ICEs. One promising concept is the Argon Power Cycle (APC), which could enable high-efficiency, zero-emission combustion in ICEs. In this approach, argon replaces air as the working fluid. Argon’s higher specific heat ratio (1.66 vs. 1.4 for air) and lower thermal conductivity both help increase efficiency. The absence of nitrogen also means NOx emissions are eliminated. The APC system is relatively simple
Kapp, Joakim, Cheng, Qiang, Vuorinen, Ville, Kaario, Ossi
Integrated Welding Simulation and Experimental Characterization of Weld-Metal and Heat-Affected-Zone Strength in AA6063-T62026-01-0230To be published on 04/07/2026
In the context of automotive lightweighting and efficient manufacturing, welding is a key joining method for aluminum body structures due to its maturity, versatility, and cost effectiveness. This study investigates MIG butt welding of AA6063-T6 sheets using a sequential thermo-mechanical finite element model with a double-ellipsoid heat source. Thermocouple histories and macroscopic metallography of the weld-pool morphology are used to validate the predicted temperature field, and post-weld deformation measured by a coordinate measuring machine is compared with the simulation to confirm overall model reliability. Hardness mapping across the joint partitions the material into weld metal (WM), heat-affected zone (HAZ), and base metal (BM). Miniature tensile specimens extracted along the weld provide local mechanical properties, from which linear strength–hardness relations are established. Building on these results, a five-material equivalent strength model covering WM, HAZ-I, HAZ-II
Shao, Jiyong, Meng, Dejian, Xiang, Yao, Gao, Yunkai
Predicting Tensile Properties of Cast Stainless Steels via Machine Learning2026-01-0237To be published on 04/07/2026
In the category of cast stainless steels, there are several variants per different level of addition of chromium (Cr), vanadium (V) along with some minor elements, such as molybdenum (Mo), niobium (Nb), tungsten (W) to meet the requirement of corrosion and oxidation resistance. However, the influence of chemical composition variations on the mechanical properties of cast SS continues to lack a clear understanding. In the present study, via machine learning (ML), the effects of each element on the tensile properties of the cast stainless steel are studied. The ML model is then used to predict how variations in elements affect tensile behavior, with the predictions validated through physical testing.
Mishra, Neelam, Biswas, Surjayan, V S, Rajamanickam, Aluru, Phani, Liu, Yi, Akbari, Meysam, Coryell, Jason
Thermal Finite Element Modelling and Prediction of Laser Welded Battery Packs2026-01-0385To be published on 04/07/2026
Battery modules consist of battery cells electrically joined at the terminals by conductive busbars. Laser welds are the most consistent and controllable process to create these connections on a large scale due to their control over power, laser width, speed, wobble, and overlap, and their quality is critical to battery pack performance. Tuning these parameters for an application typically requires weld trials to reach desired weld width, penetration, and strength without overheating the battery cell and weakening the dielectric insulators around the terminals. Poorly welded cells in a module can result in increased electrical resistance, causing greater joule heating and accelerated cell aging, and poorly welded modules can lead to uneven aging and unpredictable performance. To better understand the laser welding process, a modelling approach was developed to predict weld properties to reduce production time, costs, and potential cell damage. The 3D finite element model was calibrated
Contreras, Luis, Hoffmeyer, Matthew, Abidin, Zainal
Comparison of Formability Performance Between CR550LA and CR590DP2026-01-0178To be published on 04/07/2026
While rapid development of advanced high strength steels (AHSS) for a safer and lighter vehicle has been a primary focus in the automotive industry, the application of traditional high strength low alloy (HSLA) steel continues to be actively supported and developed. AHSS are often used to replace HSLA steels for downgauging while maintaining similar or better performance in crashworthiness and durability. However, recent developments have enabled the availability of higher strength, cold-rolled HSLA steels that could offer opportunities for a more balanced solution between material cost and material performance. Certain higher strength HSLA steels not only offer a cost-effective way to increase the strength-to-weight ratio but also provide comparable formability and better weldability to AHSS. In this study, cold rolled HSLA grades of CR340LA, CR420LA, and CR550LA are evaluated in overall formability and in-use performance when compared to CR590 dual phase (DP) grade. The evaluations
Shih, Hua-Chu, Brown, Lindsay, Pednekar, Vasant, Shi, Ming, Tedesco, Sarah
ANN and RSM-Driven Optimization of Tribological Characteristics of CuO-Doped Castor Oil Biolubricant2026-01-0353To be published on 04/07/2026
The development of renewable and eco-friendly biolubricants can address the environmental challenges posed by petroleum-based lubricants. At the same time, it is possible to improve the tribological properties of lubricants through alternative sources. To overcome these problems, castor oil is a potential basis for biolubricants due to its high viscosity, natural lubricity, and biodegradability. In the current work, castor oil was chemically modified by the epoxidation process. This process has improved the tribological properties of castor oil through the epoxidation method. In this method, the presence of hydrogen peroxide, acting as a catalyst, converts the unsaturated double bonds present in the oil into oxirane rings. At the same time, this modification enhanced the thermal stability and tribological applications in harsh operating conditions. The tribological behavior of the bio-lubricant was evaluated using a four-ball tribometer test. In the present test, pressure, temperature
Prabhakaran, J, Pali, Harveer Singh, SINGH, Nishant Kumar
Design Optimization and Dimensional Tolerance Improvement of Expanded Polypropylene (EPP) for Enhanced Automotive System Integration2026-01-0248To be published on 04/07/2026
Historically, EPP has required larger dimensional tolerances and much thicker cross-sections than solid plastics produced by injection molding, vacuum forming, and blow molding. This has proved challenging when attempting to incorporate EPP into a wider variety of automotive applications. JSP has developed multiple grades of EPP that achieve tolerances at thinner cross-sections, once considered difficult to attain. These grades expand the potential for automotive applications by combining the established benefits of EPP with improved dimensional precision. This tighter control enables advances in part design and performance, including reduced wall thicknesses, improved surface appearance, reduced weight, lower cost, part consolidation, and more efficient molding with an improved processing window, resulting in faster cycle times and reduced utility consumption. At the vehicle level, these improvements contribute to lighter overall weight for reduced carbon footprint, as well as
Sopher, Steven, Parker, Joshua
Mechanical Properties of Elastomeric Foam-Based Compression Pads for Battery Pack Applications2026-01-0247To be published on 04/07/2026
With the increasing adoption of electric vehicles (EVs) worldwide, ensuring the long-term reliability and performance of the battery systems has become a paramount engineering challenge. Lithium-ion cells exhibit dimensional changes throughout their operational life, characterized by reversible “breathing”—expansion and contraction during charge and discharge cycles—and irreversible swelling due to aging. Compression pads are critical components for ensuring the lifetime performance of battery packs. The primary function of a compression pad is to act as a compliant cushion between cells. It accommodates these volumetric fluctuations by exerting consistent and optimized pressure. By absorbing the stress from cell expansion and maintaining structural integrity within the module, compression pads mitigate degradation mechanisms and ultimately maximize the durability and safety of the battery system over thousands of cycles. This paper highlights the importance of tailoring elastomeric
Deng, Weilin, Gunashekar, Subhashini
Sheet, Polychlorotrifluoroethylene (PCTFE), Molded, UnplasticizedAMS3646E (Current)3/25/2026
This specification covers a 100% homopolymer of polychlorotrifluoroethylene (PCTFE) in the form of molded sheet 0.250 inch (6.35 mm) and under in nominal thickness.
AMS P Polymeric Materials Committee
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