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Viewing 151 to 180 of 9002
2017-03-28
Journal Article
2017-01-0302
Saeid Nasheralahkami, Sergey Golovashchenko, Scott Dawson, Raj Sohmshetty
Abstract In recent years, implementation of dual phase (DP) Advanced High Strength Steels (AHSS) and Ultra High Strength Steels (UHSS) is increasing in automotive components due to their superior structural performance and vehicle weight reduction capabilities. However, these materials are often sensitive to trimmed edge cracking if stretching along sheared edge occurs in such processes as stretch flanging. Tool wear is another major issue in the trimming of UHSS because of higher contact pressures at the interface between cutting tools and sheet metal blank caused by UHSS’s higher flow stresses and the presence of a hard martensitic in the microstructure. The objective of the present paper is to discuss the methodology of analyzing die wear for trimming operations of UHSS components and illustrate it with some examples of tool wear analysis for trimming 1.5mm thick DP980 steel.
2017-03-28
Journal Article
2017-01-0299
Chandra Jalluri, Himanshu Rajoria, Mark Goderis, Michael Habel, Trevor Hill
Abstract Thermal growth of spindle and other components is common in CNC machines, especially with MQL machining, and directly impacts positioning accuracy and thereby quality. A common method to address this is by measuring the thermal growth using gage bore probing and then compensating for it. Application of this method in 5-axis CNC machines is relatively new and effectiveness is often not tested. Error sources due to various orientations of the part could arise. A new artifact based method is presented for assessment of thermal compensation used by the CNC OEM. The method involves an artifact, test cycle and automated data logging. A precision granite artifact with gage bores on different faces is fabricated and can be presented for probing in different orientations. The machine is warmed up using repeated dry-cycling, thereby creating thermal growth. Compensation error is evaluated as the difference of actual thermal growth and compensation offset.
2017-03-28
Journal Article
2017-01-0306
Brandon M. Hance
Abstract Until now the hole expansion ratio has been generally regarded as a relative “local formability” parameter with limited application to edge-cracking analysis and prediction. In this study a constrained statistical test data analysis methodology is introduced, where the lower-bound hole expansion ratio is the basis for three practical edge-cracking failure criteria. The Maximum Edge Stretch Criterion is directly compatible with CAE simulation. The Edge Thinning Limit Criterion and the Critical Thickness Criterion are more useful in field work and post mortem laboratory failure analysis. Two case studies are described, where hole expansion test data are used to analyze edge cracking of Advanced High Strength Steel (AHSS) in real-world automotive seating applications.
2017-03-28
Journal Article
2017-01-0303
Ran Cai, Xueyuan Nie, Jingzeng Zhang
Abstract Light-weighting of vehicles is one of the challenges for transportation industry due to the increasing pressure of demands in better fuel economy and environment protection. Advanced high strength steels (AHSS) are considered as prominent material of choice to realize lightweight auto body and structures at least in near term. Stamping of AHSS with conventional die materials and surface coatings, however, results in frequent die failures and undesired panel surface finish. A chromium nitride (CrN) coating with plasma nitriding case hardened layer on a die material (duplex treatment) is found to offer good wear and galling resistances. The coating failure initiates from fatigue cracking on the coating surface due to cyclic sliding frictions. In this work, cyclic inclined sliding wear test was used to imitate a stamping process for study on development of coating fatigue cracking, including crack length and spacing vs. sliding-cycles and sliding energy densities.
2017-03-28
Journal Article
2017-01-0315
Yueqian Jia, Yangyang Qiao, Hao Pan, Edmund Chu, Yuanli Bai
Abstract A comprehensive plasticity and fracture model was built for metal sheets with application to metal sheet forming and vehicle crash simulations. The combined Bai-Wierzbicki (BW [1]) and CPB06ex2 [2] (or Yld2000-2D [3]) anisotropic plasticity model was further extended to consider elevated temperature effects in additional to the effect of multiaxial stress states. A fully modularized framework was established to combine isotropic, kinematic, and cross hardening behaviors under non-linear loading conditions. The all strain based modified Mohr-Coulomb (eMMC) fracture model was used to consider material anisotropy and nonlinear strain path. The model has been implemented into Abaqus/Explicit as a user material subroutine (VUMAT). Test results on advanced high strength steels, aluminum alloy sheets and magnesium alloy sheets are used to validate the modeling and testing methodologies. Very good correlation was observed between experimental and simulation results.
2017-03-28
Journal Article
2017-01-0310
Wei Wu, Dajun Zhou, Donald Adamski, Darryl Young, Yu-Wei Wang
Abstract The die wear up to 80,800 hits on a prog-die setup for bare DP1180 steel was investigated in real production condition. In total, 31 die inserts with the combination of 11 die materials and 9 coatings were evaluated. The analytical results of die service life for each insert were provided by examining the evolution of surface wear on inserts and formed parts. The moments of appearance of die defects, propagation of die defects, and catastrophic failure were determined. Moreover, the surface roughness of the formed parts for each die insert was characterized using Wyko NT110 machine. The objectives of the current study are to evaluate the die durability of various tooling materials and coatings for flange operations on bare DP 1180 steel and update OEM tooling standards based on the experimental results. The current study provides the guidance for the die material and coating selections in large volume production for next generation AHSSs.
2017-03-28
Journal Article
2017-01-0342
Benjamin Möller, Alessio Tomasella, Rainer Wagener, Tobias Melz
Abstract The cyclic material behavior is investigated, by strain-controlled testing, of 8 mm thick sheet metal specimens and butt joints, manufactured by manual gas metal arc welding (GMAW). The materials used in this investigation are the high-strength structural steels S960QL, S960M and S1100QL. Trilinear strain-life curves and cyclic stress-strain curves have been derived for the base material and the as-welded state of each steel grade. Due to the cyclic softening in combination with a high load level at the initial load cycle, the cyclic stress-strain curve cannot be applied directly for a fatigue assessment of welded structures. Therefore, the transient effects have been analyzed in order to describe the time-variant material behavior in a more detailed manner. This should be the basis for the enhancement of the fatigue life estimation.
2017-03-28
Journal Article
2017-01-1705
Hua-Chu Shih, Dajun Zhou, Bruce Konopinski
Abstract The hole piercing process is a simple but important task in manufacturing processes. The quality requirement of the pierced hole varies between different applications. It can be either the size or the edge quality of the hole. Furthermore, the pierced hole is often subject to a secondary forming process, in which the edge stretchability is of a main concern. The recently developed advanced high strength steels (AHSS) and ultra high strength steels (UHSS) have been widely used for vehicle weight reduction and safety performance improvements. Due to the higher strength nature of these specially developed sheet steels, the hole piercing conditions are more extreme and challenging, and the quality of the pierced hole can be critical due to their relatively lower edge stretching limits than those for the conventional low and medium strength steels.
2017-03-28
Journal Article
2017-01-0126
Joshua W. Finn, John R. Wagner
Abstract Hybrid vehicle embedded systems and payloads require progressively more accurate and versatile thermal control mechanisms and strategies capable of withstanding harsh environments and increasing power density. The division of the cargo and passenger compartments into convective thermal zones which are independently managed can lead to a manageable temperature control problem. This study investigates the performance of a Peltier-effect thermoelectric zone cooling system to regulate the temperature of target objects (e.g., electronic controllers, auxiliary computer equipment, etc) within ground vehicles. Multiple thermoelectric cooling modules (TEC) are integrated with convective cooling fans to provide chilled air for convective heat transfer from a robust, compact, and solid state device. A series of control strategies have been designed and evaluated to track a prescribed time-varying temperature profile while minimizing power consumption.
2017-03-28
Journal Article
2017-01-1276
Aditi Moorthy, Robert De Kleine, Gregory Keoleian, Jeremy Good, Geoff Lewis
Abstract The problem of accessibility to public transit is well-documented in transportation theory and network literature, and is known as the last mile problem. A lack of first and last mile transit services impairs access to public transit causing commuters to opt for private modes of transit over public modes. This paper analyzes the implications of a shared autonomous vehicle (AV) taxi system providing last mile transit services in terms of environmental, cost, and performance metrics. Conventional public transit options and a hypothetical last-mile shared autonomous vehicle (SAV) system are analyzed for transit between Ann Arbor and Detroit Wayne County Airport for life cycle energy, emissions, total travel time, and travel costs. In the case study, energy savings from using public transit options with AV last mile service were as high as 37% when compared to a personal vehicle option.
2017-03-28
Journal Article
2017-01-0400
Theo Rickert
Abstract Hole drilling is a very common technique for measuring residual stresses. Adding an orbiting motion of the drill was found to improve hole quality in difficult to drill materials and has been in practice for decades. This study compares measurements using various orbiting amounts. Each measurement was repeated twice to evaluate measurement statistics. There is a distinct, though relatively small, effect of the hole shape when no orbiting is used. It disappears already when the hole is 50% larger than the tool size. Different orbiting amounts also produce systematically different results. These may be related to the absolute hole size.
2017-03-28
Journal Article
2017-01-0625
Yen-Chung Liu, Brian Sangeorzan, Alex Alkidas
Abstract The purpose of this research was to measure and correlate the area-average heat transfer coefficients for free, circular upward-impinging oil-jets onto two automotive pistons having different undercrown shapes and different diameters. For the piston heat transfer studies, two empirical area-average Nusselt number correlations were developed. One was based on the whole piston undercrown surface area with the Nusselt number based on the nozzle diameter, and the other was based on the oil-jet impingement area with the Nusselt number based on the oil-jet effective impingement diameter. The correlations can predict the 95% and 94% of the experimental measurements within 30% error, respectively. The first correlation is simpler to use and can be employed for cases in which the oil jet wets the whole piston undercrown. The latter may be more useful for larger pistons or higher Prandtl number conditions in which the oil jet wets only a portion of the undercrown.
2017-01-10
Technical Paper
2017-26-0168
Ajeet Babu P K, Jibin Babu, M R Saraf
Abstract Forging is a metal forming process involving shaping of metal by the application of compressive forces using hammer or press. Forging load of equipment is an important function of forging process and the prediction of the same is essential for selection of appropriate equipment. In this study a hot forging material i.e. 42CrMo4 steel is selected which is used in automotive components like axle, crank shaft. Hot forging experiments at 750°C are carried out on cylindrical specimens of aspect ratio 0.75 and 1.5 with true height strain (ln (ho/hf)) of 0.6. Forging load for the experiments is calculated using slab and upper bound deformation models as well as Metal forming simulation using commercially available FEA software. The upper bound models with 30% deviation from the simulation results are found to be more accurate compared to the slab models.
2017-01-10
Technical Paper
2017-26-0173
Surbhi Bhagwat, Vinod Kumar Mannaru
Abstract Forging is one of the traditional bulk metal forming processes used extensively in the automotive industry. Forging has a distinct advantage versus other metal manufacturing processes in terms of strength, grain orientation, reliability, near net shape with lower material utilization, and machining requirements leading to cost effectiveness, etc. Today, the automotive industry is going through the critical phase of reducing component costs through material reduction and optimized tool consumption. With this challenge, process modeling is gaining more momentum in the industry to optimize blank size and improve the tool life with required part quality, while also evaluating press tonnage requirements for effective equipment usage. It also enables integrated process modeling by understanding the microstructure, residual stress/deformation built into the manufactured part, and integrating with material property changes for subsequent part performance prediction.
2017-01-10
Technical Paper
2017-26-0175
Muhammad Ali Siddiqui, Hein Koelman, Prashant Sharad Shembekar
Abstract Composite manufacturing in the automotive industry is striving for short cycle times to be competitive with conventional manufacturing methods, while enabling significant weight reductions. High Pressure Resin Transfer Molding (HP-RTM) is becoming one of the processes of choice for composite applications due to its ability to enable high speed part production. In this regard, researchers need to offer differentiated ultra-fast curing resin systems for carbon fiber composites for automotive structural and nonstructural applications to enable Original Equipment Manufacturers (OEMs) to meet their large volume lightweight targets in concert with present day low-carbon footprint legislations. In order to expand applications for composites in the automotive industry it is necessary to optimize all aspects of the production cycle using predictive modeling.
2017-01-10
Technical Paper
2017-26-0238
Abhijit Kumbhar, Jagannath M Paranjpe, Nagesh Karanth
Abstract New process development of forging component requires in-depth knowledge and experience related to the process. Also it requires number of physical trials to arrive at optimum process and initial billet dimensions. With the help of reliable computer simulation tool, it is possible to optimize the complete forging process and billet dimensions. Simulation provides much more insight about the process and possible forging defects. This saves considerable time and money. This paper describes about a complete forging process designed for a complex component. With the help of metal forming simulation software, complete forging process was simulated and optimized. Forging defects were removed during optimization of the process. Billet weight optimization was also carried out. Deciding the preforming shape of the billet was the main challenge. An innovative pre-forging shape was arrived which resulted in eliminating one process stage.
2017-01-10
Journal Article
2017-26-0222
Vishal Vasantrao Chaudhari, V Radhika, R Vijay
Abstract First time right vehicle performance and time to market, remains all automotive OEMs top priority, to remain competitive. NVH performance of product communicates impression to customer, remains one of the most important and complex attribute to meet, considering performances to be met for 20 Hz -6000 Hz. Frontloading techniques (FEM/BEM/SEA/MBD) for NVH are critical and necessary to achieve first time right NVH performance. Objective of this paper is to present a frontloading approach for automotive sound package optimization (absorber, barrier and damper elements) for SUV vehicle. Current process of designing sound package is mainly based on experience, competitive benchmarking of predecessor products. This process (current process) heavily depend on testing and validation at physical prototype and happens at later stages of program, especially on tooled up body.
2016-11-08
Journal Article
2016-32-0024
Daisuke Sugio, Shinpei Okazaki, Mitsuo Kaneko
Abstract Glass fiber reinforced plastic of polyamide is applied as one of the materials used for the high strength exterior parts of a motorcycle, such as a rear grab rail or a carrier, to which both strength and good exterior appearance are required. However, Glass Fiber reinforced Polypropylene (PPGF), which is relatively inexpensive material, has a property that the contained glass fibers are prone to be exposed at the surface and, therefore, the requirements for good appearance are hardly met by using PPGF. In this study, Heat and Cool molding method (H&C molding) was employed to realize a cost reduction by using PPGF yet without applying painting process, and the established method was applied to mass production while fulfilling the requirements for a good exterior appearance. In H&C molding, the metal molds are heated up by steam and cooled down by water after molding.
2016-10-25
Technical Paper
2016-36-0360
Lucas Pintol Nishikawa, André Caetano Melado, Hélio Goldenstein, Luiz Felipe Bauri, Dinecio dos Santos Filho, Eduardo Nunes
Abstract The Austempering heat treatment is a well-known solution to improve the mechanical properties of ductile cast irons, therefore being referred as 'ADI' (Austempered Ductile Iron). The improved mechanical properties of ADI's with respect to conventional ductile iron is attributed to its resulting microstructure, which contains mainly carbide-free bainite with stabilized retained austenite. More recently, ductile cast irons were submitted to another heat treatment, known as 'Quenching and Partitioning' (Q&P). In this case, the ductile cast iron is austenitized, quenched to a temperature between Mf and Ms temperatures and subsequently heated to a temperature above Ms in order to partition the carbon from the martensite to the remaining austenite. The resulting microstructure comprises mainly low carbon martensite, austenite (stabilized by the carbon partition) and carbide-free bainite. Such microstructure resulted in equal or better properties than ADI.
2016-10-25
Technical Paper
2016-36-0370
André Baroni Selim, Bruno Aquino de Lyra
Abstract This work aims to demonstrate a cooling package selection for an agricultural machine equipped with Diesel engine considering different radiators area / material and fan blade angles, pursuing the best match of performance, cost and weight. It was investigated two types of radiators made from copper-brass and aluminum, two types of charge air cooler varying the dimensions and four types of fans varying the blade angle. The selection method chosen was the experimental testing. The tests were performed according to the standard SAE and internal procedures at MWM Motores Diesel laboratories located at São Paulo / Brazil. When compared with cooper-brass, the aluminum radiator presents worse heat exchange performance what makes its size increase in order to compensate the gap. Even with bigger size, the aluminum radiator keeps lighter and cheaper.
2016-10-25
Technical Paper
2016-36-0372
Bahr Rogerio, Weller Tiago
Abstract The product development process in the automotive industry is constantly subject to several studies focused on trying to minimize the costs and reduce the time to product. However, it can be said that there's very little focus on the opportunity that lays in the CAD Automation possibilities through the use of a method called Knowledge Based Engineering (KBE), which consists in its core essence on the reuse of knowledge gained during previous projects, as well as a set of best design practices, applied through automation methods and artificial intelligence in the CAD models. The CAD process automation could represent a significant reduction in the project hours in the automotive product development, mainly because the processes related to it are well defined and structured. Besides that, new automotive products are usually predictable and systemic, allowing room for an efficient CAD automation.
2016-10-25
Technical Paper
2016-36-0303
Frederico Fernandes Reis, Valdir Furlanetto, Gilmar Ferreira Batalha
Abstract To highlight the importance of resistance spot weld in the automotive industry, it's important know that a vehicle has on average 4,000 welding spots [BROWN; SCHWABER 2000] and based on worldwide vehicle production in 2015 with 90.78 million vehicles produced [OICA, 2015], were performed more than 363 billion welding spots. The number of machines in manual and automatic workstations (robots), based on 20 points by equipment and production of 45 vehicles / hour add up more than 20 million of welding machines in all over world. According new production lines are being introduced using the adaptive dynamic resistance control the welding constant current control are being replaced, so understand this technology and know implement it with efficiency needs a deep knowledge in how dynamic resistance works and correlate his behavior with the problems that causes failures in welding, so is necessary give for the welding engineers this knowledge.
2016-10-25
Technical Paper
2016-36-0224
Carla Lima, Filipe Andrade, Cristina Kawakami, Cristiane Gonçalves, Walmir Peraro
Abstract The microcellular foam injection molding process is being widely applied by the thermoplastics industry. This process consists in a melted polymer injection mixed with a processing solvent, that is an inert gas in the supercritical state, usually CO2 or N2 producing a microcellular foam. This technique offers many advantages such as weight reduction, dimensional uniformization and less warpage. Besides that, it offers a satisfactory property like acoustic and thermal insulation. On the other hand, the parts from this process have an inferior mechanical property like ductility and toughness if compared with solid injection molded parts. Nevertheless, the main issue for this process is the poor appearance quality. This paper presents a review of some existing methods for surface quality improvement as Co-injection process, where a skin is injected over the microcellular part, and Heat & Cool that consists in a control of mold temperature.
2016-10-25
Technical Paper
2016-36-0230
Guilherme Canuto da Silva, Paulo Carlos Kaminski
Abstract Automotive industries are undergoing a transformation of their manufacturing systems. Called by the German government as Industrie 4.0, this transformation is based on the evolution of traditional Embedded Systems-ES to Cyber-Physical Systems-CPS. In the next years such evolution will have to reach transitory stages, where ES and CPS should coexist for a determined period of time (ES-CPS). Based on this projection, this work compares ES with CPS, identifies the main differences between these systems and thus forms a transitory stage of automotive manufacturing for the next years. The work is structured as follows: Introduction section places the reader on the treated subject and presents the methodology of the work. Later, Industrie 4.0, Embedded Systems (ES) and Cyber-Physical systems (CPS) are defined. Once this is done, the analysis of ES-CPS transition is finished. Analysis results are presented and a representation of ES-CPS transition is proposed.
2016-10-25
Technical Paper
2016-36-0235
Juliana Lima da Silva Lopes, Cleber Albert Moreira Marques, Genildo de Moura Vasconcelos, Rafael Barreto Vieira, Flavio Fabricio Ventura de Melo Ferreira, Marcelo Henrique Souza Bomfim
Abstract This paper approaches the use of machine vision as an automation tool for verification tests in automotive Instrument Panel Cluster (IPC). A computer integrated with PXI modular instruments, machine vision software and Integrated Development Environment (IDE) composes the test system. The IPC is verified in closed-loop using the Hardware-in-the-Loop (HiL) technique in which the HiL system simulates all Electronic Control Units (ECUs) that interact with the IPC. Every simulated ECUs signals are sent to the IPC over CAN (Controller Area Network) bus or hardwired I/O using PXI modules integrated with IDE and its responses are captured by cameras. Using machine vision such images are subjected to Digital Image Processing (DIP) techniques as pattern matching, edge detection and Optical Character Recognition (OCR), which can be applied to interpret speedometer, tachometer, fuel gauges, display and warning lights.
2016-10-25
Technical Paper
2016-36-0121
Raphael Gonçalves, Rubens Pinati, Rodrigo Godoi
Abstract Distortion is an intrinsic and undesired effect of the welding process, inducing residual stresses and hence, reducing the fatigue life of the welded structure. This distortion however, does not occurs simultaneously among the entire structure; instead, it occurs gradually during the execution of the welding chord. Due to this, equal structures, but composed by weld chords executed in a different sequencing, presents different residual stresses and therefore, different fatigue performances. This study proposes a method, using finite elements model (CAE), to capture the non-linear distortions of distinct welding sequences and contrast the diverse impacts in fatigue life.
2016-10-25
Technical Paper
2016-36-0159
Mauro Iurk Rocha, Ivna Oliveira da Cruz, Maria Clara Kremer Faller, Antônio Carlos Scardini Villela, Sergio Roberto Amaral, Frederico Braz Silva, Sillas Oliva Filho
Abstract Vehicles manufacturers, in search of cost reduction, fill the tanks of recently manufactured vehicles with the least volume of fuel necessary for future commercialization. The adoption of such practice, depending on the diesel fuel storage conditions, may lead to oxidation products formation in the fuel system and to problems during the first start of these vehicles. Some vehicles manufacturers, trying to minimize the occurrence of these problems, replace the diesel fuel in the vehicle tank with new fuel when vehicle storage time reaches 90 days. As a result of such occurrences, the opportunity for a first fill diesel fuel development, that presented better oxidation stability during storage, was identified.
2016-10-25
Technical Paper
2016-36-0169
Emilio C. Baraldi, Paulo Carlos Kaminski
Abstract The competition among automotive industries increases each year worldwide. Among their diverse needs, what can be highlighted are: market expansion, model diversification, competitive prices, customer-recognized quality, new products release in shorter time periods, among others. The occurrence of flaws that might compromise the health or safety of the product’s user is admittedly one of the largest issues for any manufacturer, especially if these flaws are identified after its commercialization (recall). In this work, a study on recall in the automotive industry in the Brazilian market will be presented, comprising the years of 2013 and 2014. Reasons and causes of recall are addressed, based on the sample of the aforementioned research, with special emphasis on flaws derived from the production process. The conclusion at the end of the work is that the final assembly in the automotive manufacturing process is what requires more attention from engineering area.
2016-10-25
Technical Paper
2016-36-0149
Edinilson Alves Costa
Abstract Mainly in the last 30 years so much research has been done on Fe-based calculation of seam welded thin-sheet structures fatigue life. However, available prediction methods have been developed for a limited range of geometries under ideal load conditions. Extrapolating to complex real world geometries and load conditions such those resultant from, for example, ground vehicles dislocation over rough surfaces, are least documented. One example of the application of seam welded thin-sheet structures in the ground vehicle industry is the powertrain installation bracketry. Such brackets are subject to variable amplitude loading sourced from powertrain and road surface irregularities and their fatigue strength is tightly dependent on the strength of their joints. In this paper, a FE-based force/moment method has been used for numerically predicting fatigue life of powertrain installation bracketry of a commercial truck submitted to variable amplitude loading.
2016-10-25
Technical Paper
2016-36-0171
Leandro Brasil Araujo, Juliano Tessaro, Renan Sardim
Abstract Due to financial global crisis started in 2008 and intensified in the past years in Brazil, the maintenance of a good company’s financial situation is a big challenge and it is more relevant in actual moment. Because of expected turbulent scenario for the next years, it is necessary to adopt strategies to mitigate risks that involve Supply Chain impacting industrial production. In this way, it is crucial adopt strategies and actions that assist to evaluate the performance of suppliers and its associate potential financial risk, what can be considered a companies’ success differential factor during crisis period as well. In this scenario, MWM Motores Diesel adopts an internal process of monitoring the risk of suppliers based on internally developed tools and others available at market.
Viewing 151 to 180 of 9002