Browse Topic: Manufacturing

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In this work, a modified Ahmed body with both upsweep and downsweep was used to create a complex wake. The time-averaged streamline topology revealed that the wake was composed primarily of a torus past the vertical base and two pairs of streamwise-oriented vortices on the upper and lower slant edges. Several vortex identification methods including three-dimensional (3D) (Q−, λ2−, Ω−criteria, and Liutex method) and two-dimensional (2D) (Γ1−criterion) methods were compared to determine the effectiveness in identifying complex wake structures. Of the 3D methods analyzed, none produced wholly satisfactory results. The Q− and λ2−criteria were plagued by well noted issues; failing to separate shear from rotation and threshold sensitivity which led to inconsistently identifying the weaker torus. The Ω−criterion addressed all of these concerns, especially identifying the torus consistently. However, the identified torus structure did not reflect the physical structure observed using the
Aultman, MatthewDuan, Lian
Wind tunnel calibration is necessary for repeatable and reproducible data for all industries interested in their output. Quantities such as wind speed, pressure gradients, static operating conditions, ground effects, force and moment measurements, as well as flow uniformity and angularity are all integral in an automotive wind tunnel’s data quality and can be controlled through appropriate calibration, maintenance, and statistical process control programs. The purpose of this technical paper is to (1) provide a basis of commonality for automotive wind tunnel calibration, (2) help customers and operators to determine the calibration standards best suited for their unique automotive wind tunnel and, (3) complement the American Institute of Aeronautics and Astronautics recommended practice R-093-2003(2018) Calibration of Subsonic and Transonic Wind Tunnels as specifically applied to the automotive industry. This document compiles information from various automotive wind tunnel customers
Bringhurst, KatlynnBest, ScottNasr Esfahani, VahidSenft, VictorStevenson, StuartWittmeier, Felix
Reduction of frictional losses by changing the surface roughness in the form of surface textures has been reported as an effective method in reducing friction in the boundary regime of lubrication. Laser-based micro texturing has been mostly used to create these texture patterns and it is reported that it can reduce the frictional resistance by ~20-50%. However, the use of laser-based techniques for texture preparation led to residual thermal stress and micro cracks on the surfaces. Hence, the current study emphasizes using conventional micromachining on piston material (Al alloy Al4032) to overcome this limitation. Three variations of semi-hemispherical geometries were prepared on the surface of Al alloy with dimple depths of 15, 20 and 40 μm and dimple diameters of 90, 120 and 240 μm. Prepared textured surfaces with untextured surfaces are compared in terms of wear, wettability, and friction characteristics based on Stribeck curve behaviors. Results of this investigation demonstrated
Sahu, Vikas KumarShukla, Pravesh ChandraGangopadhyay, Soumya
Opening a tailgate can cause rain that has settled on its surfaces to run off onto the customer or into the rear loadspace, causing annoyance. Relatively small adjustments to tailgate seals and encapsulation can effectively mitigate these effects. However, these failure modes tend to be discovered relatively late in the design process as they, to date, need a representative physical system to test – including ensuring that any materials used on the surface flow paths elicit the same liquid flow behaviours (i.e. contact angles and velocity) as would be seen on the production vehicle surfaces. In this work we describe the development and validation of an early-stage simulation approach using a Smoothed Particle Hydrodynamics code (PreonLab). This includes its calibration against fundamental experiments to provide models for the flow of water over automotive surfaces and their subsequent application to a tailgate system simulation which includes fully detailed surrounding vehicle geometry
Gaylard, Adrian PhilipWeatherhead, Duncan
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
Tang, HaiyuanXu, DexingSun, XiaowangWang, XianhuiWang, LiangmoWang, Tao
Modern military operations prove that increased terrain mobility is critical for heavy tracked vehicles’ (HTVs) survivability and lethality. HTV major system packaging as a component of preliminary design with many physical constraints and assumptions poses great challenges for mobility. This paper develops an approach and a method that accounts for such constraints/assumptions and optimizes the packaging of the HTV system assembly, including vehicle armor, armament and munition, powertrain, and fuel tanks. The optimization purpose is to accommodate the center of gravity for improving ground pressure distribution and then reducing the sinkage. This work is based on a literature review and combines numerous techniques rooted in Western literature and Eastern Soviet- and post-Soviet-era literature. The optimization process is developed using a genetic algorithm. The Mean Relative Design (MRD) parameter is proposed to study the average system rearrangement (i.e., re-packing) that is
Vardi, HaggayVantsevich, VladimirGorsich, David
As stepper motors become more and more widely used in engineering systems (vehicles, 3-D printers, manufacturing tools, and similar), the effects of their induced magnetic fields present a concern during the packing and orientation of components within the system. For applications requiring security, this is also a concern as the background electromagnetic radiation (EMF) can be captured at a distance and used to reproduce the motion of the motor during operation. One proposed alternative is to use customized non-magnetic plastic shields created using additive manufacturing. Some small studies have been completed which show some effectiveness of this approach but these studies have been small-scale and difficult to reproduce. To seek a more rigorous answer to this question and collect reproducible data, the present study used full factorial design of experiments with several replications. Three materials were used: Polylactide (PLA), PLA with 25% (weight) copper powder, and PLA with 15
Hu, HenryPatterson, Albert E.Karim, Muhammad FaeyzPorter, LoganKolluru, Pavan V.
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, MeysamWang, AndyWang, QiguiYan, Cuifen
The metal inert-gas (MIG) welding technique employed for aluminum alloy automotive bumpers involve a complex thermo-mechanical coupling process at elevated temperatures. Attaining a globally optimal set of model parameters continues to represent a pivotal objective in the pursuit of reliable constitutive models that can facilitate precise simulation of the welding process. In this study, a novel piecewise modified Johnson-Cook (MJ-C) constitutive model that incorporates the strain-temperature coupling has been proposed and developed. A quasi-static uniaxial tensile model of the specimen is constructed based on ABAQUS and its secondary development, with model parameters calibrated via the second-generation non-dominated sorting genetic algorithm (NSGA-II) method. A finite element simulation model for T-joint welding is subsequently established, upon which numerical simulation analyses of both the welding temperature field and post-welding deformation can be conducted. The results
Yi, XiaolongMeng, DejianGao, Yunkai
In recent years, the stronger push for reducing GHG and NOx emissions has challenged vehicle manufacturers globally. In USA, Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light Duty and Medium-Duty Vehicles released by EPA in April 2023 aims to reduce the CO2 emissions by 56% and 44%, respectively, for light and medium duty vehicles by 2032 from 2026 levels. It also includes the NMOG+ NOx standards, which require a 60 – 76% reduction by 2032 from 2026 levels for light to medium-duty vehicles. Europe also aims to reduce CO2 emissions by 55% by 2030 from 1990 levels and 100% by 2035. To achieve such low levels of CO2 emissions, especially in the near-term scenario of limited EV sales, hybridization of conventional powertrains has found renewed interest. While hybrid powertrains add complexity, if optimized well for the application, they can offer best tradeoff between upfront cost, range, payload, performance, emissions and off-ambient operation. This study
Fnu, DhanrajCorreia Garcia, BrunoPaul, SumitJoshi, SatyumFranke, Michael
A new method for bearing preload measurement has shown potential for both high accuracy and fast cycle time using the frequency response characteristics of the power transmission system. One open problem is the design of the production controller, which relies on a detailed sensitivity study of the system frequency response to changes in the bearing and system design parameters. Recently, an analytical model was developed for multi-row tapered roller bearings that includes all appropriate bearing and power transmission system design parameters. During the assembly process, some of the parameters related to the roller positions cannot be controlled. These parameters include the actual position of the first roller compared to the vertical axis, the relative position of the rollers between the bearing rows, and others. This work presents a sensitivity analysis of the effects of those uncontrollable parameters on the analytical model. The sensitivity study determines the percentage change
Gruzwalski, DavidMynderse, James
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, WilliamLi, ChengzhiSchwarz, JacksonLakhtakia, AkhleshBakis, CharlesEl-Sayegh, ZeinabEl-Gindy, Moustafa
To obtain real-time tire wear status during vehicle operation, this paper proposes a tire wear detection method based on signal analysis. Firstly, PVDF piezoelectric thin film sensors are pasted in the center of the airtight layer of tires with different degrees of wear to collect tire stress data under different working conditions. Secondly, filter and extract the time-domain and frequency-domain feature information of the collected data to construct a feature dataset. Finally, a deep regression model is established to train the feature dataset and achieve real-time detection of tire damage status. The results indicate that the prediction algorithm based on signal analysis and feature extraction achieves a maximum error of 0.3mm in tire wear detection, demonstrating high accuracy in tire wear detection. Providing tire information for safe driving of vehicles has high industrial application value.
Xianyi, XieYang, HaoJin, Lisheng
To promote the electric performance and safety of development for EV mobility, optimization methodology and design guide of high voltage bolted joint should be newly developed. This paper describes the development process of multi-physics (electrical, mechanical, thermal) FEA methodology, various experimental tests and establishment of optimization methodology of busbar bolted joint design in terms of bolt preload validation and joint temperature rise. The various key factors on high voltage joint tightening are quantitatively studied by utilizing this optimized methodology.
Lee, Joon HaWu, ZhijunGerini-Romagnoli, MarcoNassar, Sayed
For electrical vehicle (EV) automotive body-in-white (BIW) structures, protection of passengers and battery in crash event becomes equally important. In addition to energy absorption, intrusion protection for battery and vehicle becomes extremely important and GPa advanced high strength steels (AHSS) including press hardened steels (PHS), DP/MP/CP/GEN3 steels have become material of choice for design for those components. Higher yield strength materials especially in 980/1180MPa MP and CP category are chosen for part design over conventional low yield strength DP. In this study, the forming characteristics including both global and local formability are evaluated and compared among 980 DP/MP grades. Formability test such as forming limit curve (FLC), true fracture strain, V bend, half dome, and hole expansion tests are conducted. Microstructure analysis to understand the effect of different grain structure and phases of DP/MP grades is also accomplished. A T-shape laboratory die trials
Shih, Hua-ChuPednekar, VasantShi, MingSingh, JatinderTedesco, SarahWu, Wei
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, DoraUrbanic, Ruth Jill
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, ChengZhang, MingWang, TaoZhang, Tang-yunCao, CanWang, Liangmo
Since aluminum alloys (AA) are widely used as structural components across various industries, higher requirements for shape-design, load-bearing, and energy-absorption capacity have been put forward. In this paper, we present the development of a numerical model, integrated with a compensation method, that effectively predicts processing defects in the bumper beam of a vehicle, resulting in a marked improvement in its forming quality. Specifically, different constitutive models are investigated for their applicability to the beam, enabling a precise evaluation of its structural performance under large deformation. The Johnson-Cook failure model is introduced to better characterize the fracture behavior of the beam under severe structural damage. The three-point bending experiment served as a rigorous examination, demonstrating good consistency between the experimental and simulation results. Furthermore, a prediction model for assessing the forming quality during the bending process
Zhang, ShizhenMeng, DejianGao, Yunkai
The automotive industry is amidst an unprecedented multi-faceted transition striving for more sustainable passenger mobility and freight transportation. The rise of e-mobility is coming along with energy efficiency improvements, greenhouse gas and non-exhaust emission reductions, driving/propulsion technology innovations, and a hardware-software-ratio shift in vehicle development for road-based electric vehicles. Current R&D activities are focusing on electric motor topologies and designs, sustainability, manufacturing, prototyping, and testing. This is leading to a new generation of electric motors, which is considering recyclability, reduction of (rare earth) resource usage, cost criticality, and a full product life-cycle assessment, to gain broader market penetration. This paper outlines the latest advances of multiple EU-funded research projects under the Horizon Europe framework and showcases their complementarities to address the European priorities as identified in the 2Zero
Armengaud, EricRatz, FlorianMuñiz, ÁngelaPoza, JavierGarramiola, FernandoAlmandoz, GaizkaPippuri-Mäkeläinen, JenniClenet, StéphaneMessagie, MaartenD’amore, LeaLavigne Philippot, MaevaRillo, OriolMontesinos, DanielVansompel, HendrikDe Keyser, ArneRomano, ClaudioMontanaro, UmbertoTavernini, DavideGruber, PatrickRan, LiaoyuanAmati, NicolaVagg, ChristopherHerzog, MaticWeinzerl, MartinKeränen, JanneMontonen, Juho
Gray 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 its good characteristics, in relation to lubrication, heat conductivity and damping. Engine parts particularly 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 of the cyclic material behavior of GJL materials. Within a comprehensive study, different GJL materials have been investigated at Fraunhofer LBF to provide more detailed information regarding the influence of size effects on fatigue strength. Accordingly, a variety of specimen
Bleicher, ChristophKansy, Axel
Vibration qualification tests are indispensable for vehicle manufacturers and suppliers. Carmakers’ specifications are therefore conceived to challenge the mechanical endurance of car components in the face of numerous in-service detrimental phenomena: In automotive industries, components are commonly qualified by means of a test without failure, the goal being to determine whether it will or not "pass" customer requirements. Validation of newly designed components is obtained via bench test and structural simulation. Simulation has gained traction in recent years because it represents the first step of the design validation process. In particular, FEA simulations are powerful to predict the dynamic behavior of physical testing on prototypes, enable engineers to optimize the design and predict the durability. This paper illustrates how FEA simulations were applied to product validation in the pre-serial phase to optimize manufacturing process. In particular, we will focus on the PCB of
Duraipandi, Arumuga PandianLeon, RenanBonato, MarcoRaja, Antony VinothKumar, LalithNiwa, Takehiro
The suspension Kinematics & compliance (K&C) characteristic test bench can simulate the excitation of the road to the wheels under various typical working conditions in a quasi-static manner on the bench, enabling the measurement of the K&C characteristics of the suspension system without knowing the specific suspension structure form, parameters, etc., assisting in the entire design process of the vehicle. In this paper, aiming at various geometric source errors existing in the processing and assembly process of the K&C characteristic test bench, an evaluation method based on the homogeneous transformation matrix is proposed to establish the position error of the center of the end loading disk in the series motion chain. Firstly, the mapping relationship between the position error of the end loading disk in the series mechanism kinematic chain and the assembly error is established by using the homogeneous transformation matrix. Then, the change matrix of the coordinate system from the
Sun, HaihuaDuan, YupengWu, JinglaiZhang, Yunqing
High-efficiency manufacturing involves the transmission of copious amounts of data, exemplified both by trends in the automotive industry and advances in technology. In the automotive industry, products have been growing increasingly complex, owing to multiple SKUs, global supply chains and the involvement of many tier 2 / Just-In Time (JIT) suppliers. On top of that, recalls and incidents in recent years have made it important for OEMs to be able to track down affected vehicles based on their components. All of this has increased the need for OEMs to be able to collect and analyze component data. The advent of Industry 4.0 and IoT has provided manufacturing with the ability to efficiently collect and store large amounts of data, lining up with the needs of manufacturing-based industries. However, while the needs to collect data have been met, corporations now find themselves facing the need to make sense of the data to provide the insights they need, and the data is often unstructured
Jan, JonathanPreston, JoshuaJuncker, John
A passenger vehicle hood is designed to meet Vulnerable Road User (VRU) regulatory requirements and consumer metric targets. Generally, hood inner design and its reinforcements, along with deformable space available under the hood are the main enablers to meet the Head Impact performance targets. However, cross functional balancing requirements, such as hood stiffness and packaging space constraints, can lead to higher Head Injury Criteria (HIC15) scores, particularly when secondary impacts are present. In such cases, a localized energy absorber is utilized to absorb the impact energy to reduce HIC within the target value. The current localized energy absorber solutions include the usage of flexible metal brackets, plastic absorbers etc. which have limited energy absorbing capacity and tuning capability. This paper focuses on usage of a novel 3D printed energy absorbers, based on various kinds of lattice structures. These absorbers are either sandwiched between the inner and the outer
Kinila, VivekanandaAgarwal, VarunV S, RajamanickamTripathy, BiswajitGupta, Vishal
In order to comply with the tightening of global regulations on automobile exhaust gas, further improvements to exhaust gas control catalysts and upgrades to on-board diagnostics (OBD) systems must be made. Currently, oxygen storage capacity (OSC) is monitored by front and rear sensors before and after the catalyst, and deterioration is judged by a decrease in OSC, but it is possible that catalyst deterioration may cause the rear sensor to detect gas that has not been sufficiently purified. It is important to observe the activity changes when the catalyst deteriorates in more detail and to gain a deeper understanding of the catalyst mechanism in order to create guidelines for future catalyst development. In this study, we used a μ-TG (micro thermogravimetric balance) to analyze in detail how differences in design parameters such as the type of precious metal, detection temperature, and mileage (degree of deterioration) affect the OSC rate in addition to the OSC of the ceria-based
Hamada, ShotaUegaki, ShinyaTanabe, HidetakaNakayama, TomohitoJinjo, ItsukiKurono, SeitaOishi, ShunsukeNarita, KeiichiOnishi, TetsuroYasuda, KazuyaMatsumura, DaijuTanaka, Hirohisa
In automotive engineering, seam welds are frequently used to join or connect various parts of structures, frames, cradles, chassis, suspension components, and body. These welds usually form the weaker material link for durability and impact loads, which are measured by lab-controlled durability and crash tests, as well as real-world vehicle longevity. Consequently, designing robust welded components while optimizing for material performance is often prioritized as engineering challenge. The position, dimensions, material, manufacturing variation, and defects all affect the weld quality, stiffness, durability, impact, and crash performance. In this paper, the authors present best practices based on studies over many years, a rapid approach for optimizing welds, especially seam welds, by adopting Design For Six Sigma (DFSS) IDDOV (Identify, Define, Develop, Optimization, and Verification) discrete optimization approach. We will present the case testimony to show the approach throughout
Qin, Wenxin (Daniel)
Battery cell aging and loss of capacity are some of the many challenges facing the widespread implementation of electrification in mobility. One of the factors contributing to cell aging is the dissimilarities of individual cells connected in a module. This paper reports the results of several aging experiments using a mini-module consisting of seven 5 Ah 21700 lithium-ion battery cells connected in parallel. The aging cycle comprised a constant current-constant voltage charge cycle at a 0.7C C-rate, followed by a 0.2C constant current discharge, spanning the useful voltage range from minimum to maximum according to the cell manufacturer. Charge and discharge events were separated by one-hour rest periods and were repeated for four weeks. Weekly reference performance tests were executed to measure static capacity, pulse power capability and resistance at different states of charge. All diagnostics were normalized with respect to their starting numbers to achieve a percentage change
Swarts, AndreSalvi, Swapnil S.Juarez Robles, Daniel
Blistering in aesthetic parts poses a significant challenge, affecting overall appearance and eroding brand image from the customer's perspective and blister defects disrupt painting line efficiency, resulting in increased rework and rejection rates. This paper investigates the causes and effects of blistering, particularly in the context of internal soundness of Aluminum castings, emphasizing the crucial role of Computed Tomography in defect analysis. Computed Tomography is an advanced Non-Destructive Testing technique used to examine the internal soundness of a material. This study follows a structured 7-step QC story approach, from problem identification to standardization, to accurately identify the root Cause and implement corrective actions to eliminate blister defect. The findings reveal a strong link between internal soundness and surface quality. Based on the root cause, changes in the casting process and die design were made to improve internal soundness, leading to reduced
D, BalachandarNataraj, Naveenkumar
In sheet metal simulation, computation time is significantly influenced by the number of elements used to discretize the sheet blank, which covers the shape of forming tool geometry. Based on particle kinematics, motion of material point is modeled, and the concept of zero circumferential motion material line (ZML) is proposed. The slope ratio of material line (SRML) is proposed to quantify the circumferential deviation for determining the ZML. Based on the SRML, a method is developed to segment sheet blank and apply constraints. The method is demonstrated through forming simulation on a Hishida geometry. The proposed method, with its minimal to no circumferential motion along ZMLs, exhibits high level of accuracy retention while simultaneously impressively reducing computation time (up to 77%). This combination of efficiency and precision makes it a compelling approach for reducing simulation cost.
Sheng, ZiQiangAsimba, BrianCabral, Kleber
The current ASTM A653 standard for determining the bake hardening index (BHI) of sheet metals can lead to premature fracture at the transition radius of the tensile specimen in high strength steel grades. In this study, a new test procedure to characterize the BHI was developed and applied to 980 and 1180 MPa third generation advanced high strength steels (3G-AHSS). The so-called KS-1B methodology involves pre-straining over-sized tensile specimens followed by the extraction of an ASTM E8 sample, paint baking and re-testing to determine the BHI. Various pre-strain levels in the range of 2 to 10% were considered to evaluate the KS-1B procedure with select comparisons with the ASTM A653 methodology for pre-strain levels of 2 and 8%. Finally, to characterize the influence of paint baking at large strain levels, sheared edge conical hole expansion tests were conducted. The tensile mechanical properties of the 3G steels after paint baking were observed to be sensitive to the pre-strain with
Northcote, RhysBerry, AvalonNarayanan, AdvaithTolton, CameronLee, HaeaSmith, JonathanMcCarty, EricButcher, Cliff
Roller bearings are used in many rotating power transmission systems in the automotive industry. During the assembly process of the power transmission system, some types of roller bearings (e.g., tapered roller bearings) require a compressive preload force. Those bearings' rolling resistance and lifespan strongly depend on the preload set during the installation process. Therefore, accurate preload setting can improve bearing efficiency, increase bearing lifespan, and reduce maintenance costs over the life of the vehicle. A new method for bearing preload measurement has shown potential for high accuracy and fast cycle time using the frequency response characteristics of the power transmission system. One open problem is the design of the production controller, which relies on a detailed sensitivity study of the system frequency response to changes in the bearing and system design parameters. Recently, an analytical model was developed for multi-row tapered roller bearings that includes
Gruzwalski, DavidMynderse, James
The initial powder used for the manufacturing of NdFeB permanent magnets is usually prepared through rapid cooling, either by melt spinning or strip casting. The powders produced by these two methods are suitable for different applications: while melt-spun powder is a good initial material for bonded and hot-deformed magnets, strip-cast powder is normally used for sintered magnets. To investigate the suitability of using strip-cast powder to manufacture hot-deformed magnets, NdFeB powder prepared by strip casting was hot pressed (without particle alignment) and compared with melt-spun powder prepared under the same conditions (700 °C, 45 MPa, 90 min). Although the processing parameters are the same (pressed in the same mold), the magnetic properties of the magnets made from the two powders are significantly different. Surprisingly, the magnet made from the strip-cast powder (after ball milling) shows comparable magnetic properties to those of isotropic magnets, with coercivity (HcJ) of
He, YouliangSong, ShaochangWalsh, DanBernier, FabriceMozharivskyj, YurijPeng, Philip
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, SiruiKang, YingziXia, ZhaoYu, ChaoLi, JianxiangShangguan, Wen-Bin
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, ViníciusHoriuchi, Lucas NaoGoncalves, Ana PaulaDe Andrade, MarinaPolkowski, Rodrigo
Combined with a modified Zener-Hollmon parameter, a recently proposed ductile failure criterion is further improved to predict the forming limit of boron steel at hot stamping temperatures. The ductile failure criterion takes into account the critical damage at localized necking or at fracture as a function of strain path and initial sheet thickness. The modified Zener-Hollomon parameter accounts for both effect of varying strain rate and temperature for Boron steel. Working FEM simulation, the capability of the ductile failure criterion is further demonstrated by predicting forming limit of a boron steel in an isothermal Nakajima dome test. Comparison shows the prediction matches quite well with the measurement.
Sheng, ZiQiangMallick, Pankaj
To address the issue of signal aliasing when multiple particles pass through a metallic particle sensor, which can lead to misidentification of particle count, we employ numerical simulation methods for an in-depth investigation. We developed a mathematical model of a three-coil inductive metal particle sensor to explore the signal variations induced by the passage of a single particle. We utilized micro-element simulation analysis to dissect the signal generated by a single particle, elucidating the underlying change process. Focusing on dual ferromagnetic particles as the subject of study, we conducted simulations and demodulation of the induced voltage under various combinations of sizes and spacings to investigate the influence patterns of dual adjacent ferromagnetic particles on the sensor's induced signal. Further research into the peak signals of different diameter particles at a constant spacing revealed that, for a given spacing, the ratio of peak signals between particles of
Chen, SenShen, YitaoQiang, GuiyanZheng, ZhengWang, ZheyuHao, YinHu, Ting
Door sunshade in a vehicle has proven to be very comfortable and luxurious feature to the customers. Luxury vehicles provide power sunshade which is electrically operated with the activation of a switch, whereas cost conscious vehicles provide manual sunshade which requires manual coiling and uncoiling. This study is to develop a door panel structure that can accommodate both the manual sunshade and power sunshade, thereby serving both cost conscious as well as luxury seeking customers. Manual sunshade consists only of cassette, pull bar, spindle mechanism and hooks whereas the power sunshade consists of cassette, pull bar, spindle mechanism, flap mechanism, bowden cable mechanism, actuator and motor. Due to this difference in package, it becomes difficult to accommodate both variants of sunshade into the same body system. However, this study helps in developing a common body structure by ways of effective packaging, modifying the cable and actuator mechanism and critical packaging of
S M, Rahuld, AnanthaKakani, Phani Kumar
In-Mold Graining (IMG) is an innovative production technology applied to the skin wrapping of automotive interior components. In the design of automotive interior components of door panels and instrument clusters, to overcome process-related problems, such as the thinning of grain patterns and excessive reduction in thickness, simulation of the skin vacuum forming process is required. The Thermoplastic Olefin (TPO) skin material is investigated in this paper, and a viscoelastic mechanical model for this material is established. Dynamic Mechanical Analyzer (DMA) is utilized to perform scan for frequency and temperature, and the tested data is used to obtain key model parameters of the viscoelastic constitutive model. Based on the experimental data, the study explores how to calculate the relaxation time spectrum to describe the viscoelastic properties of TPO material during the vacuum forming process. Numerical simulation of the vacuum forming process of TPO material is conducted using
Chai, BingjiGuo, YimingXie, XinxingZhang, Qu
Parts in automotive exhaust assembly are joined to each other using welding process. When the exhaust is subjected to dynamic loads, most of these weld joints experience high stresses. Hence it should be ensured that the exhaust assembly is designed to meet the requirements of exhaust durability for the estimated life of the vehicle. We also know that all parts used in manufacturing of exhaust system have inherent variations with respect to sheet metal thickness, dimensions and shape. Some parts like flex coupling and isolators have high variations in their stiffness based on their material and manufacturing processes. This all leads to a big challenge to ensure that the exhaust system meets the durability targets on a vehicle manufactured with all these variations. This works aims to evaluate the statistical spread in weld life of an exhaust with respect to inherent variations of its components. For the purpose of variational analysis, a Design of Experiments (DOE) is done where
Ramamoorthy, RajapandianBazzi, Ramzi
The final step in manufacturing high-precision parts for internal combustion engines, such as cylinder heads and blocks, is the removal of machining chips from the finished parts. This step is crucial because the machining chips and cutting oil left on the surface after machining can cause quality issues in the downstream engine assembly and affect the cooling system’s performance during engine operation. This chip removal step is especially critical for parts with internal cavities, such as the water jackets in cylinder heads, due to the difficulty of removing chips lodged in the narrow passages of these internal channels. To effectively remove chips from the water jacket, machining chip washing systems typically utilize multiple high-velocity water jets directed into the water jacket, creating flows with substantial kinetic energy to dislodge and evacuate the machining chips. For machining chip washing systems equipped with dozens of water nozzles, optimizing washing efficiency
Jan, JamesTorcellini, SabrinaKhorran, AaronHall, Mark
Solid state joining processes are attractive for magnesium alloys as they can offer robust joints without the porosity issue typically associated with welding of magnesium and dissimilar materials. Among these techniques, Self-Piercing Riveting (SPR) is a clean, fast and cost-effective method widely employed in automotive industry for aluminum alloys. While SPR has been proven effective for joining aluminum and steel, it has yet to be successfully adapted for magnesium alloy castings. The primary challenge in developing magnesium SPR technology is the cracking of the magnesium button, which occurs due to magnesium's low formability at room temperature. Researchers and engineers approached this issue with several techniques, such as pre-heating, applying rotation to rivets, using a sacrificial layer and padded SPR. However, all these methods involve the employment of new equipment or introduction of extra processing steps. The aim of this work is to develop a SPR technique which adapts
Tabatabaei, YousefWang, GerryWeiler, Jonathan
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