Browse Topic: Materials properties

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Exploring Bionic Twisted TPMS Designs for Improved Energy Absorption2026-01-0243To be published on 04/07/2026
Triply periodic minimal surface (TPMS) lattice structures have emerged as a promising class of customizable mechanical metamaterials owing to their outstanding potential in lightweight design and multifunctional engineering applications. However, previous studies have mainly concentrated on global parameters such as wall thickness, cell size, and periodicity, while the local deformation and pre-deformation characteristics of unit cells, particularly the twist effects along specific directions, have not been systematically investigated. To address this gap, a bioinspired twisted design strategy was proposed in this study, in which controllable pre-twist was introduced along the build direction to tailor the energy absorption behavior of lattice structures. Twisted lattice specimens with different twist angles were fabricated using selective laser melting, and their mechanical properties were comprehensively examined through numerical simulations and experimental validation. The results
Liu, Zhe, Lian, Yuehui, Li, Youguang, Guo, Pengbo, Zhong, Gaoshuo
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
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
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
Investigation into Dynamic Behavior of Jute-Glass-Aluminium Hybrid Polymer Composites for Automotive Applications2026-01-0245To be published on 04/07/2026
The research work in this paper investigates the development and dynamic characterization of lightweight hybrid polymer composites tailored for automotive applications. Fiber-reinforced polymer composites, owing to their high specific strength and stiffness, have emerged as promising candidates to replace conventional materials. Expanding on the current trend of hybridization that blends natural and synthetic fibers to optimize mechanical strength and vibration-damping behavior, this study incorporates aluminum perforated sheets (Al) as additional reinforcement to increase stiffness without significantly increasing weight. Jute (J) fibers, known for their inherent damping capability, were combined with glass fibers (G) and Al sheets. Six symmetric hybrid laminates G/J/Al/J/G, J/G/Al/G/J, J/J/Al/J/J, G/G/G/Al/G/G/G, and J/J/J/J/J were fabricated using hand lay-up followed by compression molding. The modal frequencies and damping properties were obtained through experimental testing
Salve, Aniket, Mache, Ashok, Nalawade, Dattatraya, Joshi, Shardul
Influences of Process Parameters on Residual Stress and Tensile Performance of Riveted Joints2026-01-0183To be published on 04/07/2026
The mechanical integrity and performance of riveted joints critically influence the reliability and safety of automotive structures. To investigate the effect of residual stress on the tensile behavior of riveted joints, this study firstly established a finite element model of the riveting process using Abaqus software. The model was validated using the thick-walled cylinder theory, and the distribution of residual stress around the rivet hole was subsequently analyzed. Orthogonal experiments were subsequently conducted to examine the influence of key process parameters including rivet spacing, hole diameter, and upset head height on tensile performance, yielding simulation results for both radial residual stress and maximum tensile load. Based on the finite element analysis results, XGBoost and Kriging surrogate models were established using four key parameters as input variables, namely rivet spacing, hole diameter, upset head height, and arrangement pattern, with radial residual
Shen, yunlong, Zhan, Zhenfei, Tang, Weiqin, Yang, Yutong, Xiao, yong, HUANG, SHIYAO
Development of Full Articulation Subsystem FEA Model for Validating Vehicle Suspension Durability2026-01-0190To be published on 04/07/2026
Vehicle durability is a cornerstone of automotive engineering, directly impacting customer satisfaction, brand reputation, and warranty costs. Traditionally durability validation of suspension systems often rely on virtual validation of individual components (an approach which can overlook complex non-linear system interactions) and followed by expensive full vehicle physical tests which happen very late in the vehicle development phase, which often results in correlation gap between virtual and physical realms, resulting in components redesigning and production delays. This paper presents a more efficient, high-fidelity, full-articulation suspension subsystem finite element (FE) model development specifically for durability assessments. This integrated model enables comprehensive block cycle durability assessments, providing a holistic understanding of system behavior and eliminating the inefficiencies of analyzing components in isolation. This methodology yields significant
Bavgi, Sai Kiran
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
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
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
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
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
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
Exploring biomimetic structures with multi-level mechanical properties to improve energy absorption2026-01-0172To be published on 04/07/2026
In this study, a class of bio-inspired three-layer twisted meta-units was proposed and systematically investigated. Parameterized models with different sequences and angles were systematically constructed through geometric twisting mapping formulas, forming multi-level mechanical response structures that combine periodicity and twisting coupling characteristics. The study focused on the effects of twisting angle, support rod diameter, and layer height sequence on mechanical properties. The results indicate that these meta-units exhibit distinct two-stage or even multi-stage plateau stresses during compression. The initial stage is primarily dominated by rotation–buckling instability induced by anti-chiral interfaces, while the later stage is governed by the curling–collapse of homo-chiral layers. In terms of sequence arrangement, the reverse–sequential arrangement mode maintains a lower first peak load while exhibiting a wider negative Poisson's ratio range and higher specific energy
Liu, Zhe, Li, Youguang, Lian, Yuehui, Zhong, Gaoshuo, Guo, Pengbo
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
Mechanical Performance and Deformation Mechanisms of Hybrid Cylindrical TPMS Lattices with Gradient Wall Thickness2026-01-0484To be published on 04/07/2026
Lattice metamaterials possess lightweight, high strength, and excellent energy absorption, making them promising for engineering applications. Their mechanical properties can be tuned by cell topology and structural design. This study proposes a multi-degree-of-freedom hybrid strategy for cylindrical TPMS lattices. Three uniform types (Primitive, Gyroid, IWP) were fabricated and validated through experiments and simulations. Radial, axial, and circumferential hybridizations were then explored, revealing distinct deformation and energy absorption mechanisms: CMA structures showed multi-stage behavior, while CMR and CMC offered longer plateau stages and higher stresses. Inspired by biological architectures, gradient wall thickness designs were introduced, significantly improving performance. Notably, CMR-GPI213 and CMC-PIG312 increased specific energy absorption by 24% and 14.8%, and CMA-GIP312 reduced peak force by 37.7% without sacrificing absorption. These results demonstrate that
Liu, Zhe, Guo, Pengbo, Zhong, Gaoshuo, Lian, Yuehui, Li, Youguang
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
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
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
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
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
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
Thermal Performance of Natural Fiber Hybrid Composites for Automotive Insulation Applications2026-01-0244To be published on 04/07/2026
This study investigates the thermal conductivity of natural-fiber-based hybrid polymer composites with potential automotive insulation applications. With the increasing demand for lightweight, sustainable, and thermally efficient materials in vehicle cabins, under-hood systems, and electric vehicle battery enclosures, natural fiber composites present a promising alternative to conventional glass-fiber composites. Three distinct composite configurations were fabricated: pure glass, glass-jute hybrid, and glass-jute-coir hybrid, using general-purpose polyester resin as the matrix. The composites were manufactured using the hand lay-up method. Thermal conductivity measurements were conducted using the ASTM C177 guarded hotplate method on composite plates. Results indicate that the hybrid composite with glass, jute, and coir fibres has the lowest thermal conductivity, making it the most effective for insulation applications. This study demonstrates that natural fibre-reinforced composites
Mache, Ashok, Salve, Aniket, Chinchanikar, Satish, Borse, Hardik, Deshmukh, Omkar, Mahadikpatil, Siddhi, Kulkarni, Aparna
Wear and Friction of PTFE and PEEK Coated Cast Iron for Piston Ring Application2026-01-0240To be published on 04/07/2026
In engine 30% of the total energy is lost due to the friction between piston ring and cylinder liner due to their constant rubbing motion. A piston that reciprocates at high speeds has piston rings that constantly scrape against the wall leading to high frictional losses within the engine. The engine has to work against this resistance to provide the required power, and hence it will consume more fuel. For this reason, material used for these components is more crucial. Reduction of surface friction between moving parts in order to increase overall efficiency can be achieved by suitable coating. The most commonly used piston rings are coated with chromium layers that are electroplated which is being replaced by chrome plating. Low coefficient of friction (COF) and high wear resistance can be achieved by self-lubricating coating of PTFE and PEEK polymer-based composite coatings. Experimental results showed that the PEEK and PTFE coating performed better in terms of friction and wear
Rajendran, R., Tamilarasan, T R, J, Chandradass
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
Role of Advanced Polishing Techniques in Enhancing Al–Cu Diffusion Bonding: Eliminating Impurities and Voids for High-Performance Conductive Joints2026-01-0235To be published on 04/07/2026
The demand for lightweight, high-efficiency components in electric vehicles (EVs) highlights the critical need for reliable Al-Cu joints with superior electrical and thermal conductivity. While diffusion bonding has emerged as a promising approach, interfacial impurities and voids often degrade joint quality and conductivity. In this work, we introduce a novel integration of electropolishing pretreatment with ultra-thin copper foil (<50 µm) assisted diffusion bonding to achieve cleaner, void-free interfaces. Electropolishing effectively removes surface contaminants and oxides, enabling intimate atomic contact during bonding and minimizing the formation of brittle intermetallic phases. A systematic investigation of bonding parameters temperature, pressure, and time was conducted using a custom-designed graphite clamping system. Microstructural analyses reveal that polishing plays a pivotal role in producing uniform, impurity-free interfaces, resulting in reduced intermetallic thickness
Abbasi, Hossein, Liu, Yi, Su, Jinrong, WANG, Andy, xiao, Yaohong, Wang, Qigui, CHEN, LEI
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
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
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
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
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
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
Accurate Prediction of the Mechanical Properties of Welded/Interlocked Motor Core for Reliable NVH Analysis2026-01-0241To be published on 04/07/2026
Accurate prediction of the mechanical properties of welded and interlocked motor cores is critical for reliable NVH analysis of electric drives. Unlike glue-laminated cores, which rely on adhesive bonding and exhibit relatively uniform stiffness distributions, welded or mechanically interlocked laminations introduce strong local discontinuities due to spot welds, contacts, or interlocking features. These connections significantly alter the load transfer paths across laminations, resulting in anisotropic stiffness behavior and localized stress concentrations that cannot be accurately captured by homogenization approaches developed for glue-laminated cores. To address this, a refined unit-cell (RVE) modeling framework is proposed, which explicitly incorporates welded or interlocked regions as discrete mechanical connections within the periodic lamination structure. The framework accounts for variations in weld spacing/size, interlaminar contact, and interlock geometry, enabling the
Nie, Zifeng
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
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
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
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
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
Galvanic Corrosion Susceptibility Analysis and Mitigation Strategies in Automotive Battery Packs2026-28-0018To be published on 02/12/2026
As electric vehicles continue to revolutionize transportation, ensuring the reliability of their powertrain systems and Battery Packs has become a critical focus. One key challenge is galvanic corrosion, which occurs when dissimilar metals in contact are exposed to an electrolyte, such as seashore moisture or road salt used in snow or ice zones. This corrosion can weaken structural components, compromise electrical conductivity, and reduce the lifespan of critical systems. Common areas at risk include metallic joints within battery enclosures, busbars, cooling systems, and electrical connectors. Environmental factors such as high humidity and temperature fluctuations further amplify the issue, making it a pressing concern for manufacturers. This paper aims to systematically identify critical galvanic joints within electric powertrain systems and Battery Packs and provide effective strategies to mitigate corrosion risks. Preventative measures include choosing compatible materials with
Narain, Aditya, Venugopal, Sivakumar, Gopalan, Vijaysankar, Varatharajan, Senthilkumaran
Modelling and Analysis of Complex Shaped Cracks2026-28-0048To be published on 02/12/2026
This study provides an extensive analysis through finite element analysis (FEA) on the effects of fatigue crack growth in three different materials: Structural steel, Titanium alloy (Ti Grade 2), and printed circuit board (PCB) laminates based on epoxy/aramid. A simulation of the materials was created using ANSYS Workbench with static and cyclic loading to examine how the materials were expected to fail. The method was based on LEFM and made use of the Maximum Circumferential Stress Criterion to predict where cracks would happen and how they would progress. Normalizing SIFs while a crack was under mixed loading conditions was achieved using the EDI method [84]. We used Paris Law to model fatigue crack growth using constants (C and m) for the materials from previous studies and/or tests. For example, in the case of titanium Grade 2, we found Paris Law constants with C values from 1.8 × 10-10 to 7.9 × 10-12 m/cycle and m values from 2.4 to 4.3, which illustrate differing effects of their
T, Lokesh, Bhaskara Rao, Lokavarapu
Evolution of a Novel Hybrid Stab-Link for a Born Electric Sports Utility Vehicle2026-28-0001To be published on 02/12/2026
The present study details the design evolution and failure analysis of a novel hybrid stabilizer bar link (stab link) developed for the front suspension of a born electric sports utility vehicle (SUV) platform characterized by higher gross vehicle weight (GVW), increased wheel travel, and constrained packaging space. To address these challenges, a unique hybrid stab link was designed featuring dual plastic housings at both the metal ball joint ends, connected by a steel tube, and achieving a 30% weight reduction while offering enhanced articulation angles for extremely lower turning circle diameter (TCD) of the vehicle, compared to the conventional stab link. The unique hybrid stab failed under complex loading conditions during accelerated durability testing (ADT), prompting a comprehensive investigation. The failure analysis included road load data acquisition across various stab bar diameter configurations evolved during suspension tuning, different stabilizer link designs evolved
Selvendiran, P, J, Ramkumar, Nayak, Bhargav, M, Sudhan, Patnala, Avinash
Effect of Sebastiana Rostrata Fiber Loading on the Tribological Behaviour of Polycaprolactone Biocomposite2026-28-0021To be published on 02/12/2026
This study investigates the tribological behaviour of Sesbania rostrata fiber (SRF) reinforced polycaprolactone (PCL) biocomposites using a pin-on-disc wear couple. The stationary SRF/PCL composite specimen interacted with a rotating EN31 steel disc (64 HRC), establishing the sliding wear interface in accordance with ASTM G99 standards. Composite laminates containing 10, 20, and 30 wt% SRF were evaluated at a sliding velocity of 1 m/s over a fixed distance of 1000 m under varying normal loads. The incorporation of SRF significantly enhanced the wear performance relative to neat PCL, with 20 wt% fiber loading achieving the lowest coefficient of friction and specific wear rate due to improved load transfer, stronger interfacial adhesion, and a more uniform laminate structure. In contrast, the 30 wt% composite exhibited fiber agglomeration, reduced homogeneity, and weakened fiber–matrix interactions, resulting in increased wear. SEM microstructural analysis confirmed the formation of a
Raja, K., Senthil Kumar, M.S.
Vibration Analysis of Rectangular and Circular Plates with Fixed Edges: Analytical and Computational Validation2026-28-0108To be published on 02/12/2026
This study presents a comparative investigation of the vibration characteristics of rectangular and circular plates with fixed edges using analytical, numerical, and computational approaches. Analytical models based on classical plate theory were employed to calculate natural frequencies and mode shapes, while finite element analysis (FEA) was performed in a CAE tool to provide high-fidelity simulation results. A detailed mesh convergence study confirmed numerical stability, with frequency variations below 1% between successive refinements. Analytical predictions showed excellent agreement with simulation results for lower modes, with errors as low as 0.25% for the rectangular plate and 2.65% for the circular plate. However, higher modes exhibited significant deviations, with errors reaching up to 29.01% for rectangular and 181.52% for circular geometries, highlighting the limitations of closed-form solutions in capturing complex vibrational behavior. Python-based computational tools
N, Suhas, R, Sanjay, Bhaskara Rao, Lokavarapu
Computational fluid dynamic and fatigue analysis of turbocharger turbine wheel2026-28-0070To be published on 02/12/2026
Turbochargers are essential for improving engine efficiency by compressing air and delivering it to the engine at higher pressure, thereby increasing power output. The turbine wheel in a turbocharger operates under severe mechanical and thermal stresses, making it highly susceptible to fatigue failure, which can occur even under conditions below the rated operating load. To ensure long-term reliability, detailed analysis of the turbine’s fatigue life is essential. This study combines computational fluid dynamics with fatigue analysis to predict the performance and lifespan of a turbocharger's turbine wheel, with a focus on Inconel alloys known for their durability in extreme conditions. A numerical mesh analysis, employing 1,165,610 nodes, was conducted to achieve convergence for both temperature and stress evaluations, leading to the selection of a 2 mm mesh size. Pressure contours at the turbine-fluid interface revealed a pressure range between 1.09 and 1.05 bar, with most of the
Chelladorai, Prabhu, Balakrishnan, Navaneetha Krishnan, G, Naresh, T J, Sreejaun
Titanium Alloy Bars and Forging Stock, 6.0Al - 2.0Sn - 4.0Zr - 2.0Mo, Duplex AnnealedAMS6905D (Current)2/6/2026
This specification covers a titanium alloy in the form of bars up through 3.000 inches (76.20 mm), inclusive, in diameter or least distance between parallel sides with a maximum cross-sectional area of 10 square inches (64.5 cm2) and forging stock of any size (see 8.7).
AMS G Titanium and Refractory Metals Committee
Aluminum Alloy, Rolled or Forged Rings, 5.6Zn - 2.5Mg - 1.6Cu - 0.23Cr (7075-T7351, 7075-T7352), Solution Heat Treated, Mechanically Stress Relieved, and Precipitation Heat TreatedAMS4311G (Current)2/6/2026
This specification covers an aluminum alloy in the form of rolled or forged rings up to 6 inches (152 mm), inclusive, in nominal thickness at the time of heat treatment and having an OD to wall thickness ratio of 10 or greater (see 8.6).
AMS D Nonferrous Alloys Committee
Materials for Use in Optical Parts Such as Lenses and Reflex Reflectors of Motor Vehicle Lighting DevicesJ576_202601 (Current)2/2/2026
This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances. This document establishes additional performance requirements and provides test methods and requirements to evaluate the suitability of materials intended for optical applications in motor vehicles. The tests are intended to determine physical and optical characteristics of the materials only. Performance expectations of finished assemblies, including plastic components, are to be based on tests for lighting devices, as specified in SAE Standards and Recommended Practices for motor vehicle lighting equipment. Glass and materials inclusive to the light source are not in scope for this method.
Lighting Materials Standards Committee
Quality Assurance Sampling and Testing, Carbon and Low-Alloy Steel ForgingsAMS2372J (Current)2/1/2026
This specification covers quality assurance sampling and testing procedures used to determine conformance to applicable specification requirements of carbon and low-alloy steel forgings.
AMS E Carbon and Low Alloy Steels Committee
Steel, Corrosion- and Heat-Resistant, Welding Wire, 16.5Cr - 4.5Ni - 2.9Mo - 0.10N (AM350)AMS5774F (Current)2/1/2026
This specification covers a corrosion- and heat-resistant steel in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
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