Browse Topic: Materials properties

Items (31,846)

Conceptual Design of a Superconducting Aero Electric Engine System

2025-01-0146To be published on 04/25/2025

The goal of the development of an electric aircraft engine is to create an aircraft system that achieves ultimate efficiency using hydrogen fuel instead of fossil fuels. Therefore, it is necessary to focus on reducing weight as much as possible, and this paper describes the approach to such fuel cell-powered aircraft. The authors have adopted a superconducting coreless rotating electric machine with an integrated hydrogen tank and are pursuing a target of 70kg or less for the main components of a 2MW rotating electric machine. High-temperature superconducting wires have zero electrical resistance and can carry a very high current density, but the alternating current (AC) loss generated when used in AC has been an issue in their application to rotating electric machines. In 2023, The SCSC cable was developed to be a low-AC-loss, robust, and high current cable concept, in which copper-plated multifilament coated conductors are wound spirally on a core. In addition to using this

Oyori, Hitoshi, Sakurai, Sho, Kusase, Shin, Yoshida, Yukihiro, Yoshinaga, Seiichiro, Nose, Hiroyuki, Amemiya, Naoyuki

Material Adapted Method for the Repair of Curved Thermoplastic Composite Structures by Induction Welding of Patches

2025-01-0165To be published on 04/25/2025

Thermoplastic fiber-reinforced polymer composites (TPCs) are gaining importance in aviation due to their high strength, stiffness, and recyclability. To maximize their potential, efficient repair methods are needed to maintain aircraft safety and structural integrity. This article introduces a novel repair technique for damaged TPC structures, involving the insertion of a repair patch with a susceptor material. The susceptor consists of a material with high electrical conductivity and magnetic permeability and therefore reacts stronger to the electromagnetic field than the composite, even if it is carbon fiber based. This means that the thermal energy is specifically concentrated in the repair area. The susceptor can be placed on the patch surface or in the welding zone. The process begins by identifying and preparing the damaged area, followed by precise scarfing. Care is taken to ensure that the surrounding material remains intact and that an exact stepped structure is created, which

Geiger, Markus, Glaap, Anton, May, David, Schiebel, Patrick

NVH Study of Axial Flux Motor for Electric Propulsion Systems

2025-01-8568To be published on 04/01/2025

The advancement of high-performance electrification for electric vehicle (EV) development is continuously pushing the boundaries of electric motor technology. The axial flux motor (AFM) represents a promising application for high-performance EVs, offering potential advantages including up to twice the torque density and a 50% reduction in weight compared to regular IPM radial flux motors. The distinctive "pancake" configuration and high axial forces inherent to AFMs present notable NVH challenges, yet there is a lack of research exploring NVH analysis and risk assessment. In this paper, a 10-pole and 12-slot AFM motor is designed, prototyped, and tested, demonstrating the capability to deliver 300 Nm of peak torque and 140 kW of peak power. A comprehensive finite-element model is constructed, and the orthotropic stator material properties are evaluated using modal test data. The dominant axial stator modes are identified as the source of resonances in the system responses. A three

He, Song, Jensen, William, Forsyth, Alexander, Chang, Le, Zhang, Peng, Gong, Cheng, Yao, Jian, Zou, Yusheng, Fedida, Vincent, Duan, Chengwu, GSJ, Gautam

Integrated design for body in white fabricated by additive manufacturing and its mechanical performance analysis

2025-01-8613To be published on 04/01/2025

With the development of additive manufacturing technology, the concept of integrated design has been introduced and deeply involved in the research of body design. In this paper, by analyzing the structural characteristics of the electric vehicle body, we designed a body in white with the additive manufacturing process, and analyzed its mechanical properties through finite element method. According to the structural characteristics of the body, the integrated structure was modeled in three dimensions using CATIA. For the mechanical properties of the body, the strength and stiffness of the body structure were simulated and analyzed based on ANSYS Workbench. The results show that for the strength of the body, the maximum stress of the simulation results was compared with the permissible stress, and the maximum stress was calculated to be less than the permissible stress under each working condition. For the body stiffness, the displacement of the body deformation was used to measure, and

Xu, Cheng, Zhang, Ming, Wang, Tao, Zhang, Tang-yun, Cao, Can, Wang, Liangmo

Optimization method of phase change energy storage device for electric vehicle batteries based on numerical simulation

2025-01-8603To be published on 04/01/2025

Phase change energy storage devices are extensively utilized in latent heat thermal energy storage and hold significant potential for application in the thermal management of automotive batteries. By harnessing the high-density energy storage capabilities of phase change materials to absorb heat released by the batteries, followed by timely release and utilization, there is a substantial improvement in energy efficiency. This approach aligns with the objective of promoting low-carbon environmental protection and presents an opportunity to enhance the operational performance and energy utilization efficiency of electric vehicle batteries in low-temperature conditions. However, the thermal conductivity of medium and low temperature phase change materials is poor, leading to its inefficient utilization. This paper focuses on optimizing the structure of a phase change heat exchanger in a phase change energy storage device to improve its performance. A basic design of the phase change heat

Zhang, Haonan, Sun, Mingzhe, Zheng, Haoyun, Zhang, Tianming

Load-Deflection Evaluation of Bump Stoppers Using a Machine Learning Approach

2025-01-8208To be published on 04/01/2025

The accurate prediction and evaluation of load-deflection behavior in bump stoppers are critical for optimizing driving performance and durability in the automotive industry. Traditional methods, such as extensive experimental testing and finite element analysis (FEA), are often time-consuming and costly. This paper introduces a machine learning-based approach to efficiently evaluate load-deflection curves for bump stoppers, thereby streamlining the design and testing process. By leveraging a comprehensive dataset that includes historical test results, material properties, and geometrical dimensions, various machine learning models, including Neural Networks, were trained to predict load-deflection behavior with high accuracy. This approach reduces the reliance on extensive physical testing and simulations, significantly enhancing the design optimization process, leading to faster development cycles and more precise performance predictions. A case study is presented to demonstrate the

Hazra, Sandip, Tangadpalliwar, Sonali

Brittle or Ductile? Effects of Print Orientation and Raster Angle on Polylactic Acid (PLA) Fused Filament Fabrication (FFF) Tensile Samples

2025-01-8335To be published on 04/01/2025

The automotive industry leverages Fused Filament Fabrication (FFF) -based Additive Manufacturing (AM) to reduce lead time and costs for prototypes, rapid tooling, and low-volume customized designs. This paper examines the impact of print orientation and raster angle on the tensile properties of Polylactic Acid (PLA), selected for its ease of use and accessibility. Dog bone samples were designed to the ASTM D638 tensile testing standard and printed solid with a 0.2 mm layer height, two outer walls, and varying raster-fill angles, with layers alternating by 90°. Testing was conducted on the MTS Criterion Model 43, 50 kN system. Varying print orientation along the X and Y axes (double angle builds) produced a Young's modulus (YM) range of 0.7519, reflecting a 34.42% increase between the witnessed minimum and maximum values. These builds exhibited more brittle behavior than most single angle builds, except for X10 Y10 Z0 at a 45° raster (the lowest recorded YM) and X0 Y15 Z0 at a 30

Strelkova, Dora, Urbanic, Ruth Jill

Deep Learning-Based Intelligent Tire Wear Detection Method

2025-01-8278To be published on 04/01/2025

In order to obtain real-time tire wear status of vehicles, this paper proposes a deep learning-based tire wear detection method. First, a PVDF piezoelectric film sensor is attached to the center of the tire airtight layer with different wear degrees to collect tire stress data under different working conditions. Secondly, the collected data is filtered, and the time domain feature information is extracted by principal component analysis to construct the feature data set. Finally, a deep regression model is established to train the feature data set to realize the real-time detection of tire damage. The results show that the tire wear detection error based on deep learning is less than 0.3mm, which has a high tire wear detection accuracy. It provides tire information for vehicle safe running and has high industrial application value.

Xianyi, Xie, Yang, Hao, Jin, Lisheng

A Chronology of Research and Events To-Date Significant to Occupant Protection in Rear-End Automobile Impacts

2025-01-8725To be published on 04/01/2025

Theory and principles of occupant protection for automobiles in rear-end collisions have experienced significant evolution over the decades. Performance of the seatback, specifically the stiffness of the structure, during such a collision has been a subject of particular interest and debate among design engineers, accident reconstruction experts, critics, etc. The majority of current seat designs rely on plastic deformation of the seatback structure to protect the occupant from the dynamics of the crash. In attempt to highlight and provide background information for understanding this subject, this work highlights significant events, research, and publications over the past five decades to illustrate how this subject, automobile design, government regulation and public opinion has evolved. It is observed that technology and design for improving rear-impact protection has received less attention than collisions of other principal directions of force. The different types of

Warner, Wyatt

Experimental Modal Study of Heavy-duty Tire Considering the Influence of Tire Inflated Pressure

2025-01-8276To be published on 04/01/2025

Truck is an important tool for road transportation, and its safety has always been widely concerned by society; Tires are the only component in the contact between a car and the road, and the safety of high-speed driving is directly affected by their vibration characteristics; In generally speaking, the mechanical properties of tires have a crucial impact on the ride, handling stability, and safety of automobiles. At the same time, active and passive safety systems such as TCS, ABS, and ESC systems of automobiles are depended on the mechanical properties of tires. Taking the 12R22.5 heavy-duty tire as the research object, a multi-channel LMS vibration tester was used to conduct modal experiment on the tire through the testing method of free suspension, single-point input and multi-point vibration pickup (SIMO). The polyreference least squares complex frequency domain method (PolyMax) is used for modal parameter identification of the heavy-duty tires to explore the variation of tire

Zhu, Chengwei, Yan, Jingjing

Innovative Methods for Predicting Material Stress-Strain Curves Based on Transfer Learning and Artificial Intelligence

2025-01-8317To be published on 04/01/2025

The mechanical properties of materials play a crucial role in predicting performance across various applications. However, traditional methods for measuring these properties often involve complex, resource-intensive, and time-consuming tests, which may be impractical in certain situations. The Small Punch Test (SPT) is a small-sample detection technique for evaluating material mechanical properties, characterized by its "non-destructive" nature: applying localized loads to small specimen samples and measuring the resulting deformation. While SPT can obtain load-displacement curves for specimens, it cannot directly reflect material mechanical properties and relies on empirical formulas for estimation. To address this challenge, we designed a specialized SPT experiment and fixture, and established a Finite Element Method (FEM) model. We developed a multi-fidelity model capable of predicting the mechanical properties of steel and aluminum alloys, representing a novel machine learning

Zou, Jie, Chen, Yechao, Li, Shanshan, Huayang, Xiang

Numerical Investigation of Gas Diffusion Layer Properties in PEMFC

2025-01-8314To be published on 04/01/2025

This study presents a comprehensive numerical analysis of the characteristics of the gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs). Fuel cells are devices that generate electricity by reacting hydrogen with oxygen. Hydrogen supplied from a high-pressure tank reacts with oxygen within the fuel cell stack, generating electricity that drives a motor. Given the diverse design requirements for fuel cells, including applications in commercial vehicles and stationary systems, efficient material design through numerical models and simulations is indispensable. The GDL, composed of carbon fibers and resin, functions as a cushion under cell compression and facilitates the transport of electrons, heat, gas, and water. Its microstructure significantly influences these properties, making precise design crucial. In this study, we automated the material exploration by varying parameters such as the diameter and quantity of carbon fibers, as well as the amount and

Ota, Yuki, Dobashi, Toshiyuki, Nomura, Kumiko, Hattori, Takuya, Maekawa, Ryosuke

Residual Stress Analysis in Arc Welded Lap Joints of High Strength Steel Sheets and Welding Wire Using Material Properties at Heating and Cooling

2025-01-8313To be published on 04/01/2025

A technical approach is presented for the precise analysis of residual stress in arc welded lap joints of high strength steel sheets. This approach involves the development of a method to measure material properties during both the heating and cooling processes. The measured material properties are then utilized in a thermal elastic-plastic finite element method (FEM) to analyze the welding residual stresses in the lap joints. The analysis accuracy is investigated by comparing the results using material properties measured during heating, cooling, or both. The maximum temperature distribution on the surface of the heat affected zone (HAZ) is measured and accurately predicted through welding thermal conduction analysis. When the material properties measured on heating only or cooling only or both were, respectively, used in thermal elastic-plastic FEM, the analyzed results showed that the stress history in arc welded joints of 780MPa high strength steel sheets are different. The

Ohnishi, Yoichiro, Sato, Kentaro, Ma, Ninshu, Narasaki, Kunio, Weihao, Li, Yasuda, Koichi

Fatigue strength of grey cast iron – new insights regarding the size effects

2025-01-8238To be published on 04/01/2025

Grey cast iron (GJL) is one of the oldest cast iron materials and is still in use in many applications in the automotive industry due to the good characteristics in relation to lubrication, heat conductivity and damping. Especially engine parts benefit from these parameters. Nevertheless, the design of these components has always been challenging in terms of maximizing material utilization for lightweight designs for components under cyclic loading. In particular, with regard to the influence of the statistical (component size), geometrical (notches) and technological (microstructural) size effects, the existing guidelines and literature lack the necessary information to provide a comprehensive understanding. Within a comprehensive study, different GJL materials have been investigated at Fraunhofer LBF to provide a more detailed information about the influence of size effects on its fatigue strength. Accordingly, a variety of specimen sizes, geometries, and microstructures were

Bleicher, Christoph, Kansy, Axel

Spectral Estimation to Quantify Road/Track Surface Degradation

2025-01-8252To be published on 04/01/2025

Track testing methods are utilized in the automotive industry for emissions and fuel economy certification. These track tests are performed on smooth road surfaces which deteriorate over time due to wear and weather effects, hence warranting regular track repaves. The study focuses on the impact of repaving on track quality and surface degradation due to weather effects. 1D surface profiles and 2D surface images at different spatial frequencies were measured at different times over a span of two years using various devices to study the repave and degradation effects. Data from coastdown tests was also collected over a span of two years and is used to demonstrate the impact of track degradation and repaving on road load characterization parameters that are used for vehicle certification tests. Kernel density estimation and non-parametric spectral estimation methods are used to visualize the characteristic features of the track at different times. In the pre-processing stage, outliers

Singh, Yuvraj, Jayakumar, Adithya, Rizzoni, Giorgio

Energy Conversion Efficacy of Neat Dimethyl Ether Combustion with Heat Release Characterization and Emission Analysis

2025-01-8417To be published on 04/01/2025

Dimethyl ether (DME) is widely regarded as a suitable energy source for compression ignition power systems because of its high reactivity. It has been widely reported that DME possesses a significantly low propensity to form soot, hindering the innate NOx-soot trade-off encountered with diesel fuel operation. Beyond the fuel-borne oxygen content of DME, its unique physical properties present a contrasting combustion behavior which may be advantageous to direct injection systems, especially concerning the mixing-controlled combustion mode. This work aims to detail the energy conversion efficacy of DME through heat release characterization and exhaust emission speciation. The tests were controlled within a single-cylinder research engine with an off-board high-pressure injection system to handle liquified DME up to 1000bar. To mitigate interference in fuel additives over the combustion behavior, the high-pressure fuel system specifically managed neat DME. The in-cylinder pressure was the

Leblanc, Simon, Cong, Binghao, Leach, Jace, Yu, Xiao, Reader, Graham, Zheng, Ming

A systematic review about heat shrink materials using nanomaterials for the automotive industry

2025-01-8329To be published on 04/01/2025

Heat shrink polymer sleeves are a type of material used in various industries for their ability to contract and fit snugly around objects when heat is applied. These tubes are typically made from materials like polyolefin or fluoropolymers, which have the property of shrinking when heated. Nanomaterials present many applications and its usage is a remarkable tool aiming to improve many properties of materials. Then, many improvements including increase of performance and price reduction may be done due to its unique properties when nanomaterials are used into heat shrink polymer sleeves. This work presents a systematic review of the state of the art on heat-shrinkable materials for the automotive industry. As a methodology, articles from the last 10 years on the subject were selected. The keywords “heat shrink” AND “nanomaterial” AND “tubes OR sleeves” were used in three different databases. “Scopus”, “Web of Science” and “MDPI”. After using the keywords, articles only in English were

Kerche, Eduardo F., Polkowski, Rodrigo, Horiuchi, Lucas, Goncalves, Everaldo

Mechanical Analysis of a Non-Pneumatic Tire’s Spokes

2025-01-8327To be published on 04/01/2025

Mechanical analysis was performed of a non-pneumatic tire, specifically a Michelin Tweel size 18x8.5N10, that can be used up to a speed of 40 km/h. A Parylene-C coating was added to the rubber spoke specimens before performing both microscopic imaging and cyclic tensile testing. Initially, standard ASTM D412 specimens type C and A were cut from the wheel spokes, and then the specimens were subjected to deposition of a nanomaterial. The surfaces of the specimens were prepared in different ways to examine the influence on the material behavior including the stiffness and hysteresis. Microscopic imaging was performed to qualitatively compare the surfaces of the coated and uncoated specimens. Both coated and uncoated spoke specimens of each standard type were then subjected to low-rate cyclic tensile tests up to 500% strain. The results showed that the Parylene-C coating did not affect the maximum stress in the specimens, but did increase the residual strain. Type C specimens also had a

Collings, William, Li, Chengzhi, Schwarz, Jackson, Lakhtakia, Akhlesh, Bakis, Charles, El-Sayegh, Zeinab, El-Gindy, Moustafa

Thermal Insulation Tiles and Sheets Based on Intergration of Recycled Plastic Waste Fibres and Epoxy Resin

2025-01-8325To be published on 04/01/2025

Plastic waste has risen to be one of the most concerning and endangering pollutants to the environment and nature in the past few years, making its effective management and reduction a major domain of focus among researchers and industrialists. This comparative study is an attempt to utilize recycled Polyethylene Terephthalate (rPET) fibres combined with Epoxy Resin in various combinations, to provide effective and low-cost insulation in moderate to low requirements. The above-mentioned components serve as viable insulators with their thermal conductivities ranging from 0.2W/mK to 0.3W/mK and 0.15W/mK to 0.35W/mK respectively. Moisture resistance of both materials and temperature resistance of Epoxy resins ranging from 120°C to 150°C (depending upon the grade of Epoxy used) indicates good stability in harsh external operating environments. While epoxy resins are not inherently flame retardants, additives are introduced for this purpose to render the composite safer to use. Moreover

Purihella, Sri Sai Krishna, Pali, Harveer Singh, Kumar, Piyush, Sharma, Ved Prakash

Sustainable automotive composites: A systematic review of dispersion methods for cotton fibers in poly(lactic acid) matrix

2025-01-8326To be published on 04/01/2025

Composite materials are created by combining two or more different materials, such as a filler or fibrous reinforcement dispersed in a polymer matrix to improve the properties that surpass those of the individual components while reducing weight, making them ideal for the sustainable development of the automotive industry. Poly(lactic acid) (PLA) has emerged as a promising polymer matrix for composites due to its ecological and biodegradable nature and good mechanical properties (tensile strength and modulus of elasticity) but limited when compared to engineering polymers such as Acrylonitrile Butadiene Styrene (ABS) and Acrylonitrile Styrene Acrylate (ASA). Cotton fibers (CF) have gained visibility as filler or reinforcement in PLA/CF composites due to their low cost, renewable sources and relatively abundance. Although, to ensure mechanical enhancement, fiber dispersion in PLA matrix is of paramount importance, often being neglected. This article aims to study how to achieve a

De Andrade, Marina, Polkowski, Rodrigo, Horiuchi, Lucas Nao, Goncalves, Ana Paula, De Oliveira, Vinícius

Image-based Machine Learning Methods in Materials Microstructure and Failure Analysis

2025-01-8324To be published on 04/01/2025

Image-based machine learning (ML) methods are increasingly transforming the field of materials science, offering powerful tools for automatic analysis of microstructures and failure mechanisms. This paper provides an overview of the latest advancements in ML techniques applied to materials microstructure and failure analysis, with a particular focus on the automatic detection of porosity and oxide defects and microstructure features such as dendritic arms and eutectic phase in aluminum casting. By leveraging image-based data, such as metallographic and fractographic images, ML models can identify patterns that are difficult to detect through conventional methods. The integration of convolutional neural networks (CNNs) and advanced image processing algorithms not only accelerates the analysis process but also improves accuracy by reducing subjectivity in interpretation. Key studies and applications are further reviewed to highlight the benefits, challenges, and future directions of

Akbari, Meysam, Wang, Andy, Wang, Qigui, Yan, Cuifen

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

2025-01-8321To be published on 04/01/2025

Plasticized polyvinyl chloride (PVC) has many applications in automotive industry including electrical harnesses, door handles, seat and head rest covers, and instrument panel (IP) and other interior trim. In IP applications, the PVC skin plays a critical role in passenger airbag deployment (PAB) by tearing along the scored edge of the PAB door and allowing the door to open and the airbag to inflate to protect the occupant. As part of the IP, the PVC skin may be exposed to elevated temperatures and ultraviolet (UV) radiation during the years of the vehicle life cycle which can affect the PVC material properties over time and potentially influence the kinematics of the airbag deployment. Chemical and thermal aging of plasticized PVC materials have been studied in the past, yet no information is found how the aging affects mechanical properties at high rates of loading typical for airbag deployment events. This paper compares mechanical properties of the virgin PVC-based IP skin material

G, Karthigan, Savic, Vesna, Ravichandran, Gowrishankar

3D Design and Analyses of an IC Engine Piston under fatigue Test Conditions using CNTs for the Next-Generation of Motorcycles

2025-01-8359To be published on 04/01/2025

CNTs play an important role in engineering applications, especially in engine pistons design for the next-generation of motorcycles. This work presents a comprehensive analyses using finite element method under actual operating conditions purpose performance evaluation of a motorcycle engine piston design, investigating the suitability of four distinct materials. Precise material properties adhering to linear elastic isotropic behavior were defined within the software environment and proposed advanced nanomaterial ensuring accurate representations of the proposed under the prescribed loading scenarios. The primary objective was to identify the optimal material choice for the piston, ensuring superior strength, minimal deformation, and lightweight characteristics essential for high-performance engine applications. Moreover interpreting and understanding the dynamic behavior of common and advanced engineering materials. Through a comprehensive evaluation of the simulation results

Ali, Salah H. R., Ahmed, Youssef G. A., Ali, Amr S.H.R.

A Methodology to Characterize the Influence of Paint Baking and Pre-Straining on the Tensile Properties and Sheared Edge Sensitivity of Third Generation Advanced High Strength Steels

2025-01-8223To be published on 04/01/2025

The existing ASTM A653 standard for characterization of the bake hardening index (BHI) involves application of a pre-strain followed by bake hardening and subsequent testing of an ASTM-E8 tensile coupon that can lead to premature fracture in steels with high strengths and lower elongations. To this end, a new test procedure is proposed with application to 980 and 1180 MPa third generation advanced high strength steels (3G-AHSS). The proposed methodology involves pre-straining over-sized tensile specimens using the so-called KS-1B geometry, which is followed by the extraction of an ASTM E8 sample from the gauge region on which the baking and secondary tensile testing are conducted. Various pre-strain levels from 2% to 10% were considered with all tests performed using the proposed methodology avoiding premature fracture compared to the ASTM A653 method that was evaluated for pre-strain levels of 2% and 8%. Finally, to characterize the influence of paint baking on regions with

Northcote, Rhys, Berry, Avalon, Narayanan, Advaith, Tolton, Cameron, Lee, Haea, Smith, Jonathan, McCarty, Eric, Butcher, Cliff

Mechanical property analysis of triply periodic minimal surface structure with a novel hybrid structure

2025-01-8215To be published on 04/01/2025

Triply periodic minimal surface（TPMS）structure, demonstrates significant advantages in vehicle design due to its excellent lightweight characteristics and mechanical properties. To enhance the mechanical properties of TPMS structures, this study proposes a novel hybrid TPMS structure by combining Primitive and Gyroid structures using level set equations. Following this, samples were fabricated using selective laser sintering (SLS). Finite element models for compression simulation were constructed by employing different meshing strategies to compare the accuracy and simulation efficiency. Subsequently, the mechanical properties of different configurations were comprehensively investigated through uniaxial compression testing and finite element analysis (FEA). The findings indicate a good agreement between the experimental and simulation results, demonstrating the validity and accuracy of the simulation model. For TPMS structures with a relative density of 30%, meshing with S3R elements

Tang, Haiyuan, Xu, Dexing, Sun, Xiaowang, Wang, Xianhui, Wang, Liangmo, Wang, Tao

Characterisation and variabilities of aerosols produced by tyres rotating on wet surfaces

2025-01-8763To be published on 04/01/2025

Understanding the formation and behaviour of aerosols generated by vehicles traveling on wet surfaces is crucial due to their impact on vehicle soiling, visibility, and autonomous driving. These aerosols can reduce visibility for other drivers, contribute to traffic accidents, and reduce the operational capabilities of sensors for driving assistance systems and future autonomous vehicles. Despite the importance of understanding the physical properties of these aerosols is crucial for testing and validating sensors for environmental perception and recognition, field data on this topic is scarce. The formation and behaviour of these aerosols are complex. A fraction of the trailing droplets and ligaments originates directly from the tyres, while the remainder is generated upon the impact of the particles ejected from the tyres with the vehicle’s surfaces, resulting in either coalescence or further disintegration. Aerodynamic forces also significantly influence the formation of these

Otxoterena, Paul, Kallhammer, Jan-Erik, Eriksson, Peter, Ronelov, Erik

Tire wear life prediction using machine learning technique

2025-01-8757To be published on 04/01/2025

As global warming and environmental problems are becoming more serious, tires are required to accomplish balanced performance such as low rolling resistance, wet braking performance, driving stability, and ride comfort, while minimizing wear, noise, and weight. Furthermore, to respond to the rapid changes in the market environment, there is a strong demand for tire performance prediction and testing methods adapted to MBD. In MBD, Magic Formula and Ftire are used in performance design to predict handling and stability and ride comfort. However, predicting tire wear life, which is affected by both vehicle and tire characteristics, is difficult. And practical prediction method for estimating tire wear life has long been awaited. So, we had proposed an experimental-based tire wear life prediction method that using actual measurement tire characteristics and an abrasive wear volume formula. This method achieves accuracy that can be practically used in the early stages of vehicle

Ando, Takashi

Comprehensive Investigation of Combustion Characteristics, Emissions, and Tribological Properties of Synthetic Kerosene (S8) in a CVCC and CRDI Research Engine

2025-01-8443To be published on 04/01/2025

There is a need to reduce both the greenhouse gas emissions of internal combustion engines, and the reliance on traditional fossil fuels like Ultra Low Sulphur Diesel (ULSD). In this research, a synthetic aviation fuel created from natural gas feedstocks using the Fischer-Tropsch process was investigated to determine its autoignition and combustion characteristics, emissions, and tribological properties. This fuel, S8, has a Derived Cetane Number (DCN) of 62, which reflects a short Ignition Delay (ID) and Combustion Delay (CD) compared to ULSD, which has a DCN of 48. However, due to the chemical properties of S8, it lacks sufficient lubrication qualities in comparison to ULSD, so addition of 3% methyl oleate by mass was used to improve lubricity. The shorter ignition delay of S8, initially observed in a Constant Volume Combustion Chamber (CVCC), was also observed in the instrumented Common Rail Direct Injection (CRDI) engine. Investigations with an He-Ne laser apparatus with Mie

Soloiu, Valentin, Willis, James, Norton, Coleman, Davis, Zachary, Graham, Tristan, Nobis, Austin

Nanocomposites made with poly(lactic acid)/cellulose nanofibers for automotive applications: the impact of annealing on 3D printed parts

2025-01-8328To be published on 04/01/2025

The advance of regulatory emission standards for light-duty vehicles, trucks and motorcycles, coupled with rising sustainability concerns, particularly United Nations' Sustainable Development Goal 12 (responsible consumption and production), has created an urgent need for lighter, stronger, and more ecological materials. Polylactic acid (PLA), a biodegradable polymer derived from plant sources, offers promising mechanical tensile strength and processability. Nanocomposites, a solution that combines a base matrix with a nanoreinforcing filler, provides a path toward developing sustainable materials with new properties. Cellulose nanofibrils (CNF) are a valuable nanofiller obtained through industrial waste or vegetal fibers, offer a promising avenue for strengthening PLA-based materials. Additive manufacturing (AM) has gained popularity due to its ability to create complex parts, prototyping designs, and to evaluate new nanocomposite materials such as PLA/CNF, showing significant

de Oliveira, Vinícius, Horiuchi, Lucas Nao, Goncalves, Ana Paula, De Andrade, Marina, Polkowski, Rodrigo

Virtual Evaluation of Ceramic Glow Plug Design using Multiphysics Simulation Approach

2025-01-8367To be published on 04/01/2025

A glow plug is generally used to assist the starting of diesel engines in cold weather condition. Low ambient temperature makes the starting of diesel engine difficult because the engine block acts as a heat sink by absorbing the heat of compression. Hence, the air-fuel mixture at the combustion chamber is not capable of self-ignition based on air compression only. Diesel engines do not need any starting aid in general but in such scenarios, glow plug ensures reliable starting in all weather conditions. Glow plug is actually a heating device with high electrical resistance, which heats up rapidly when electrified. The high surface temperature of glow plug generates a heat flux and helps in igniting the fuel even when the engine is insufficiently hot for normal operation. Durability concerns have been observed in ceramic glow plugs during testing phases because of crack formation. Root cause analysis is performed in this study to understand the probable reasons behind cracking of the

Karmakar, Nilankan, Orban, Hatem

Thermomechanical Fatigue Behavior of Gray Cast Iron

2025-01-8319To be published on 04/01/2025

Gray cast iron is a cost-effective engineering material widely used for heavy duty engine blocks and brake rotors of vehicles. Thermomechanical fatigue condition is easily achieved in vehicle operation due to the temperature fluctuation in the components in assembly condition. To speed up the design of the component, it is critical to investigate the thermomechanical fatigue (TMF) behavior of the gray cast iron. In the present study, a series of fatigue tests including isothermal low cycle fatigue (LCF) test at elevated temperatures up to 700°C, in-phase (IP) and out-of-phase (OP) TMF tests in different temperature ranges have been conducted. Because of the asymmetric behavior in tension and compression, creep behaviors in both tension and compression and oxidation are also studied. These behaviors are the key aspects to be captured in virtualization.

Liu, Yi, Lee, Heewook, Hess, Devin, Coryell, Jason

Three-body Abrasive Wear Surface Characterization of Military Diesel Engine Piston Rings and Cylinder Bores

2025-01-8346To be published on 04/01/2025

Two 50-hr engine dynamometer tests were conducted on 12-cylinder diesel military engines with differing piston ring sets. Engine A exhibited more than double the oil consumption over engine B. An investigation was conducted to explain why the oil consumption differed by employing several posttest analytical techniques including cylinder bore geometry measurements, surface metrology, wear characterization, and chemical analysis on the piston rings and cylinder wall coatings. The 3D colormaps of cylinder bore deformation showed uneven volumetric deformation through the piston stroke instead of 2D plane deformation. It was found that the primary reason of high oil consumption was direct loss of sealing between the piston, piston ring and cylinder bore due to predominately abrasive wear, three-body abrasive wear and bore polishing. Furthermore, the compromised sealing of the combustion chamber led to blow-by. Carbon deposits, corrosive byproducts, surface abrasives, loss of desired surface

Thrush, Steven, Chen, Aijie, Foley, Michael, Sebeck, Katherine, Boufakhreddine, Ziad

Material-Combined Vehicle Brake Disc Design for Enhanced Cooling Performance

2025-01-8189To be published on 04/01/2025

The improvement of heat dissipation performance of ventilated brake discs is vital of braking safety. The usual technical approaches shall be material optimization or structural improvement. In this paper, a simulation model of the heat transfer of brake discs is established using STAR-CCM+ software. Cast iron, aluminum metal matrix composite (Al-MMC) and carbon-ceramic composite materials (C-SiC) are compared. The results show that: Al-MMC have better thermal conductivity so that a more uniform temperature gradient distribution shall be formed; C-SiC have poorer heat capacity yet better thermal stability; cast iron performs better with convective heat transfer rate, which enhances the heat transfer between the surface and surrounding flow field. Based on the results, this paper proposes four types of material combined brake disc using different friction materials and geometry structures. At the level of material application, Al-MMC and C-SiC friction layer are compared. At the level

Wang, Jiarui, Jia, Qing, Zhao, Wentao, Xia, Chao, Yang, Zhigang

Driving in the Rain: Evaluating How Surface Material Properties Affect Lidar Perception in Autonomous Driving

2025-01-8016To be published on 04/01/2025

Light Detection and Ranging (LiDAR) is a promising type of sensor for autonomous driving that utilizes laser technologies to provide perceptions and accurate distance measurements to obstacles in the vehicle path. In recent years, there has also been a rise in the implementation of LiDARs in modern and autonomous vehicles to aid the self-driving features. However, navigating in adverse weather remains to be one of the biggest challenges in achieving Level 5 full autonomy due to sensor soiling, which subsequently leads to performance degradation that poses safety hazards. When driving in rain, raindrops impact the LiDAR sensor assembly and cause attenuation of signals when the light beams undergo reflections and refractions. Consequently, signal detectability, accuracy, and intensity are significantly affected. To date, limited studies were able to perform objective evaluations of LiDAR performance, most of which faced limitations that hindered realistic, controllable, and repeatable

Pao, Wing Yi, Li, Long, Agelin-Chaab, Martin, Roy, Langis, Knutzen, Julian, Baltazar, Alexis, Muenker, Klaus, Chakraborty, Anirban, Komar, John

Weldlife Variational Assessment for Exhaust System Using Monte Carlo Approach

2025-01-8198To be published on 04/01/2025

Different parts in Automotive exhaust assembly are joined to vehicle body through welding which is likely to develop significant stress at the weld locations when subjected to road dynamic loading. Needless to mention that design of these welds needs to robust enough not to fail during the life cycle of the vehicle for any variations in manufacturing and other parameters. This work aims to evaluate the variance of weldlife with respect to input variations in the exhaust system and compare the same with life requirements USING VIRTUAL ROAD LOADS. The variations in parameters such as parts thickness, shape, isolator stiffness and flex-coupling stiffness rates are considered. To predict the weldlife, exhaust connection weld elements are grouped as an individual set and evaluated. The variations in shape parameters are defined using morphing and interfaced to the GM proprietary process for creation of morphed geometry within the DOE variations. Bounds for these input variables are chosen

Ramamoorthy, Rajapandian, Bazzi, Ramzi

Study on the Influence Mechanism of Camber and Load on the Linear zone of Tire Side-slip Mechanical Properties

2025-01-8274To be published on 04/01/2025

The linear region of the side-slip mechanical properties of tires is often used in the simulation of linear monorail models for vehicles, especially in the design of active control systems. Side-slip stiffness is a key parameter in tire side-slip, and is significantly influenced by camber and load. In response to the tire industry's need for efficient acquisition of tire mechanical properties and the development of virtual prototyping technology, this paper proposes a method to address the influence mechanism of camber on side-slip in the study of tire camber side-slip prediction models. This paper analyzes the impact of camber on the linear region of tire side-slip mechanical properties at the microscopic level. It then examines the effect of camber on the side-slip condition from the perspective of tire external characteristics, combined with the tire theoretical model, to map the local characteristics of camber onto the external characteristics of tire side-slip. First, a finite

Yin, Hengfeng, Suo, Yanru, Wu, Haidong, Min, Haitao, Liu, Dekuan

Fixture Stiffness Impact on Spindle Coupled Multi-Axial Input Durability Test for Front or Rear Axle with Non-isolated Subframes

2025-01-8256To be published on 04/01/2025

The half vehicle spindle-coupled multi-axial input durability test has been broadly used in the laboratory to evaluate the fatigue performance of the vehicle chassis systems by automotive suppliers and OEMs. In the lab, the front or rear axle assembly is usually held by fixtures at the interfaces where it originally connects to the vehicle body. The fixture stiffness is vital for the laboratory test to best replicate the durability test in the field at a full vehicle level especially when the subframe of the front or rear axle is hard mounted to the vehicle body. In this work, a multi-flexible body dynamics (MFBD) model in Adams/Car was utilized to simulate a full vehicle field test over various road events (rough road, braking, steering). The wheel center loads were then used as inputs for the spindle coupled simulations of the front axle with a non-isolated subframe. Three types of fixtures including trimmed vehicle body, a rigid fixture with softer connections and a rigid fixture

Gao, Jianghua, Smith, Derek, Zhang, Xin, Yu, Xiao

Testing Complex Circuits with Radio-frequency Reflectometry

2025-01-8251To be published on 04/01/2025

Driving automation systems rely heavily on sophisticated electronics to function effectively, and economic pressure poses new challenges in manufacturing. Tightly integrated sensors, processors, and communication modules monitor and control the vehicle's operation at any time. Size, weight, power, and cost constraints put pressure on manufactures to reduce stack electronics, miniaturize boards, and innovate over the traditional sequential assemble/test cycle. Consequently, designers and manufacturers reduce access to boards, remove test points, co-locate RF with other components, and break the sequential SMT line. Radiofrequency (RF) reflectometry is a mature and reliable technology essential for characterizing materials, components, and analog circuits. It provides precise insights into electromagnetic properties like impedance and permittivity, crucial for optimizing RF and microwave designs. Widely used in fields from material science to quantum computing, RF reflectometry is key to

Moreno, Carlos, Sharma, Rakshit, Pabbi, Srijan, Fischmeister, Sebastian

Liquid Viscosity Decoupling Measurement Based on U-Shaped Tungsten Wire Sensor

2025-01-8460To be published on 04/01/2025

In this paper, based on the cylindrical flow theory of incompressible viscous fluids and the equivalent circuit model of resonant sensing elements, a theoretical model for the measurement of liquid viscosity with a U-Shaped tungsten wire resonance sensor was established. This model can measure the liquid viscosity independently without liquid density or coupled detection of liquid density. The experimental results show that the decoupling of liquid viscosity and its density can be achieved at Re<1. The liquid viscosity is strongly linear with the resonant conductance. The viscosity measurement error is less than 7.24% in the viscosity range of 7.235cP to 85.2cP.

Shan, Baoquan, Shen, Yitao, Yang, Jianguo, Wu, Dehong

Advanced Aftertreatment System Meeting Future HD CNVII Legislation II

2025-01-8478To be published on 04/01/2025

With the increasing clarity of the CNVII emission legislation, it is foreseeable that CNVII will further tighten the emissions of major pollutants such as nitrogen oxide (NOx), nitrous oxide (N2O) and PN. Together with the implementation of stage IV of fuel consumption legislation in January 2025, which requires engine fuel consumption reduction or thermal efficiency improvement, it will inevitably lead to the further deterioration of its pollutant emissions and reduction of exhaust temperature, posing greater challenges to the aftertreatment system (ATS) in terms of NOx removal during engine cold start and suppressing N2O formation. This study is an extension of our earlier investigation of “Advanced Aftertreatment System Meeting Future HD CNVII Legislation” (Wang, Y., Chen, S., Zhang, J., Chen, J. et al., "Advanced Aftertreatment System Meeting Future HD CNVII Legislation," SAE Technical Paper 2024-01-2379, 2024, https://doi.org/10.4271/2024-01-2379.), a novel copper-based corrugated

Wang, Yan, Fu, Guangxia, Chen, Shuyue, Aberg, Andreas, Jiang, Shuiyan, Zhang, Jun

Combine HD map information to enhance road topology reasoning by offline supervised training and on-line ensemble learning

2025-01-8021To be published on 04/01/2025

Topology reasoning plays a crucial role in understanding complex driving scenarios and facilitating downstream planning, yet the process of perception is inevitably affected by weather, traffic obstacles and worn lane markings on road surface. Combine pre-produced high-precision maps, and other type of map information to the perception network can effectively enhance perception robustness, but this on-line fused information often requires a real-time connection to website servers. We are exploring the possibility to compress the information of offline maps into a network model and integrate it with the existing perception model. We designed a topology prediction module based on graph attention neural network and an information fusion module based on ensemble learning. The module, which was pre-trained on offline high-precision map data, when used online, inputs the structured road element information output by the existing perception module to output the road topology, and the output

Kuang, Quanyu, Rui, Zhang, Zhang, Song, Yixuan, Gao

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

2025-01-8006To be published on 04/01/2025

In Formula SAE , the primary function of the frame is to provide structural support for the different components and withstand the applied load. Traditional truss steel tube body have drawbacks such as low strength and high weight, which has led most Formula Student teams worldwide to adopt monocoque made of carbon fiber composites, which are lighter and stronger. Enhancing the mechanical performance of carbon fiber laminates has been a key focus of research for these teams. In three point bending tests of carbon fiber laminates, the outer skin is primarily subjected to tensile forces. This results in significant stress at the adhesive layer between the skin and the core material at both ends of the laminate, leading to potential adhesive failure. Consequently, experimental boards often exhibit delamination between the outer skin and the core material, and premature core crushing, which compromises the mechanical performance of the laminate and fails to pass the Structural Equivalency

Ning, Zicheng

Exploring Hybrid TPMS Designs for Improved Energy Absorption in Vehicle Crashworthiness

2025-01-8726To be published on 04/01/2025

Triply Periodic Minimal Surface (TPMS) structures have gained significant attention in recent years due to their excellent mechanical properties, lightweight characteristics, and potential for energy absorption in various engineering applications, particularly in automotive safety. This study explores the design, manufacturing, and mechanical performance of both general and hybrid TPMS structures for energy absorption. Three types of fundamental TPMS unit cells—Primitive, Gyroid, and IWP—were modeled using implicit functions and combined to form hybrid structures. The hybrid designs were optimized by employing Sigmoid functions to achieve smooth transitions between different unit cells. The TPMS structures were fabricated using Selective Laser Melting (SLM) technology with 316L stainless steel and subjected to quasi-static compression tests. Numerical simulations were conducted using finite element methods to verify the experimental results. The findings indicate that hybrid TPMS

Liu, Zhe, Wang, MingJie, Guo, Pengbo, Li, Youguang, Lian, Yuehui, Zhong, Gaoshuo

In-situ Nanoindentation and Finite Element Analysis for Evaluating the Young’s Modulus of Anode Current Collectors in Lithium-ion Batteries

2025-01-8133To be published on 04/01/2025

As the use of lithium-ion batteries in electric vehicles becomes increasingly prevalent, there has been a growing focus on the mechanical properties of lithium-ion battery cores. The metal collector exerts a significant impact on the tensile properties of the electrode and also on the internal fracture of the cell. Tensile tests are unable to obtain the mechanical properties of the collector in situ, and the stripping process tends to cause additional damage to the collector. Therefore, nanoindentation tests are required to gain the mechanical properties of the collector. Nanoindentation testing represents the primary methodology for the determination of the mechanical properties of thin films. Commercial indentation instruments typically employ the Oliver-Pharr method for the assessment of material mechanical properties. However, this method is subject to limitations due to the constraints imposed by sample boundary conditions. In order to obtain an accurate measurement of the elastic

Dai, Rui, Sun, Zhiwei, Park, Jeongjin, Xia, Yong, Zhou, Qing

Materials Innovation in Thermal Management: Advancing Aluminum Alloy Technologies for the Next-Generation Electrical Vehicle Battery Cold Plate

2025-01-8162To be published on 04/01/2025

The rapid expansion of the global electric vehicle (EV) market has significantly increased the demand for advanced thermal management solutions. Among these, the battery cold plate is a critical component, essential for maintaining optimal battery temperatures and ensuring efficient operation. As EV batteries increase in size, the thermal management requirements become more complex, necessitating the development of new alloys with enhanced strength and thermal conductivity. These advancements are crucial for the effective dissipation of heat and the ability to withstand the mechanical stresses associated with larger and more powerful batteries. The evolving performance demands of EVs are driving material innovation within the thermal management sector. This study aims to explore global heat exchanger market trends from a materials perspective, focusing on the evolution of alloy mechanical, fatigue, and thermal properties. Specifically, we investigated the transition from traditional

Jalili, Mehdi, Wang, Xu, Razm-poosh, Hadi

A Suspension Model Based on Semi-Recursive Method and Data-Driven Compliance Characteristics

2025-01-8282To be published on 04/01/2025

Many methods have been proposed to accurately compute a vehicle’s dynamic response in real-time. The semi-recursive method, which models using relative coordinates rather than dependent coordinates, has been proven to be real-time capable and sufficiently accurate for kinematics. However, not only kinematics but also the compliance characteristics of the suspension significantly impact a vehicle’s dynamic response. These compliance characteristics are mainly caused by bushings, which are installed at joints to reduce vibration and wear. As a result, the use of relative or joint coordinates fails to account for the effects of bushings, leading to a lack of compliance characteristics in suspension and vehicle models developed with the semi-recursive method. In this research, we propose a data-driven approach to model the compliance characteristics of a double wishbone suspension using the semi-recursive method. First, we create a kinematic double wishbone suspension model using both the

Zhang, Hanwen, Duan, Yupeng, Zhang, Yunqing, Wu, Jinglai

Dynamic Testing and Analysis of Autocycle Vehicles for Accident Reconstruction

2025-01-8687To be published on 04/01/2025

The Autocycle is a style of vehicle that most often utilizes a reverse-tricycle design with two front wheels and a single rear wheel. Modern autocycles in the United States are often utilized in a recreational role. This work presents physical measurements of two modern autocycles for use in accident reconstruction and pursues a deeper understanding of the unique attributes and handling associated with these vehicles. Vehicles were used to measure physical properties and subjected to cornering tests presented herein, and the data is compared to that for a conventional automobile. Observations on tire scuff marks are made from cornering tests unique to these vehicles. Strengths and challenges with this type of vehicle design are presented for various use cases as compared to conventional automobiles. Data and knowledge from this study will aid accident reconstruction efforts and act as a stepping stone for future work.

Warner, Wyatt, Swensen, Grant, Warner, Mark

Advanced Methodology for Accelerated Durability Block Cycle Testing of Automotive Rubber Suspension Bushings and Powertrain Mounts

2025-01-8236To be published on 04/01/2025

In the field of automotive engineering, the performance and longevity of suspension bushings and powertrain mounts are critical. These components must endure fatigue loads characterized by their variable amplitude, multi-axial nature, and out-of-phase oscillations. The challenge lies in comprehensively characterizing these service loads during the early stages of vehicle production to foresee potential issues that may arise during later stages. Additional complexity in this analysis is introduced by the nonlinear hyperelastic deformation exhibited by natural rubber, a common material used in these components. To address these challenges, original equipment manufacturers (OEMs) and suppliers employ Computer-Aided Engineering (CAE) techniques for fatigue life predictions. These predictions are complemented by physical testing involving what are known as block cycles. However, the results obtained from these approaches often fail to fully represent the real loading conditions that a

Zarrin-Ghalami, Touhid, Datta, Sandip

Computational Method of Static and Dynamic Mechanical Properties of a Rolling Lobe Air Spring

2025-01-8261To be published on 04/01/2025

To investigate the static and dynamic mechanical properties of air springs and their influencing factors, two models were established in this paper to calculate the static and dynamic mechanical properties of air springs, including a simulation model based on the finite element method and a mathematical calculation model based on thermodynamic theory. First, a performance calculation model for rolling lobe air springs with aluminum tubes was established, which considered the thickness of the bellow and the impact of the inflation and assembly process on the state of the bellow. The static and dynamic mechanical properties of air springs were calculated using this model, including static load-bearing capacity and static/dynamic stiffness. The calculation results showed that both the static characteristics of the air spring under isothermal conditions and the dynamic characteristics under adiabatic conditions were able to be calculated accurately. However, the changes in dynamic

Wang, Sirui, Kang, Yingzi, Xia, Zhao, Yu, Chao, Li, Jianxiang, Shangguan, Wen-Bin

Automotive fatigue load spectra: modelization, identification and applications.

2025-01-8240To be published on 04/01/2025

Fatigue design is invariably of prior concern for the automotive industry, no matter of the evolution of the mobility market: at first because carmakers have to stay compliant with general structural integrity requirements for reliability, notably applicable to the chassis system, then due to the endless competition for lightweighting in order to mitigate product costs and/or enhance vehicle efficiency. In the past, this key performance was often tackled by basic reference load cases, making use of the simplest signal content, e.g. sinus functions, to practice constant amplitude loads on test rigs and for computations, respectively. Nowadays, full time series coming from proving ground measurements, or any corresponding virtual road load data computations, may be applied to feed complex vehicle computations for virtual assessment and complex test facilities for final approval, under variable amplitude loads. In between, the concept of load spectra (i.e. distribution of amplitudes with

Facchinetti, Matteo Luca, Tjhung, Tana, Jaffre lng, Sébastien, Datta, Sandip, Hayat lng, Romain, Guo, Mingchao

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