Criteria

Display:

Results

Viewing 241 to 270 of 19605
Technical Paper
2014-04-01
Yu Hsien Wu, Sreekanth Surapaneni, Kumar Srinivasan, Paul Stibich
Abstract Automotive vehicle body electrophoretic (e-coat) and paint application has a high degree of complexity and expense in vehicle assembly. These steps involve coating and painting the vehicle body. Each step has multiple coatings and a curing process of the body in an oven. Two types of heating methods, radiation and convection, are used in the ovens to cure coatings and paints during the process. During heating stage in the oven, the vehicle body has large thermal stresses due to thermal expansion. These stresses may cause permanent deformation and weld/joint failure. Body panel deformation and joint failure can be predicted by using structural analysis with component surface temperature distribution. The prediction will avoid late and costly changes to the vehicle design. The temperature profiles on the vehicle components are the key boundary conditions used to perform structure analysis. This paper presents an efficient method to predict vehicle body temperature profiles as the vehicle pass through the radiant section of an e-coat and/or paint oven.
Technical Paper
2014-04-01
Philip S. Blackwelder, William Chang, Jonathan Lohr
Abstract The latest generation of Computer Numerically Controlled (CNC) technology enables cost and time effective product development by minimizing the time and expertise required to fabricate precision parts. The North Carolina State University (NCSU) EcoCAR 2 team used specialized Computer Aided Design (CAD) techniques and a CNC water-jet to produce a mounting system to install a custom series-hybrid drivetrain into a 2013 Chevrolet Malibu. The team of engineering students was able to overcome a lack of resources and machining experience by leveraging the capabilities of CAD and CNC to create quality components. Complex 3D designs were broken down into 2D shapes that were precision cut from inexpensive metal plate. The design of these parts featured slot and tab interfaces that enabled parts to be self-locating and were implemented in a way that only allowed parts to be assembled in the correct orientation. The precision fit afforded by the water-jet had the additional benefit of simplifying the welding process by eliminating the need for external work holding.
Technical Paper
2014-04-01
Bartosz Flekiewicz, Marek Flekiewicz
Paper describes analysis of the design process of modern automotive LPG and CNG containers. Over decade experience in the field of both computer based analysis as well as in the real conditions testing has been collected and presented in the paper. Authors present the potentials of modern FEM methodologies in the optimization and production of lightweight steel containers. It has been proved that the most sophisticated numerical analysis have to be followed by the construction verification, particularly considering direct exposure to fire. Bonfire test have become obligatory for both liquid and compressed gases containers. Properly chosen fire protection system, together with the adequate level of quality of materials applied for its production together with proper directing of the gas flowing out from safety devices are the essential factors defining gas containers fire safety. The experience in the field of bonfire tests made it also possible to present the main issues of the proper couplings of containers with their equipment (valves).
Technical Paper
2014-04-01
Paul R. Stibich, Yu Hsien Wu, Weidong Zhang, Michao Guo, Kumar Srinivasan, Sreekanth Surapaneni
Abstract This paper describes a comprehensive methodology for the simulation of vehicle body panel buckling in an electrophoretic coat (electro-coat or e-coat) and/or paint oven environment. The simulation couples computational heat transfer analysis and structural analysis. Heat transfer analysis is used to predict temperature distribution throughout a vehicle body in curing ovens. The vehicle body temperature profile from the heat transfer analysis is applied as an input for a structural analysis to predict buckling. This study is focused on the radiant section of the curing ovens. The radiant section of the oven has the largest temperature gradients within the body structure. This methodology couples a fully transient thermal analysis to simulate the structure through the electro-coat and paint curing environments with a structural, buckling analysis. The ability to predict the buckling phenomenon using a virtual simulation will reduce the risk of late production changes to the vehicle class “A” surfaces.
Technical Paper
2014-04-01
Shailesh Mani Pandey, Qasim Murtaza, Kalpana Gupta
Abstract The functions of a piston ring are to seal off the combustion pressure, to distribute and control the oil, to transfer heat and to stabilize the piston. Most piston rings and metallic sealing rings for modern application where running conditions are severe, require some form of coating to minimise abrasion and corrosion. The piston ring coating improves the life of engine as well as fuel efficiency. In this study, physical vapour deposition (ion chrome plating) was investigated; plates with similar composition as the piston ring material were prepared by the casting process using induction arc furnace and sand mould. Wear test of the coating was conducted on pin on disc machine under dry conditions. The wear rate was calculated using mass loss methods on an electronic balance having least count of 1× 10−4 g. The wear rate of the coating was found to be increased with increase in load as well as sliding speed for the ion plating with the counter body of tungsten carbide but in the case of ion plating with the HCS & MS it is found to be decreased.
Technical Paper
2014-04-01
Kambiz Jahani, Sajjad Beigmoradi, Mohsen Bayani Khaknejad
Abstract The main objective of this study is to investigate the effect of spot-weld modeling approaches on NVH virtual simulation problems. For this purpose, finite element method is considered for further simulations. The goal is to evaluate and compare results within the domain of 0 to 200 Hz by modeling spot-welds with three different element types: a rigid body constraint element (RBE), two rigid body elements with hexahedral solid element (RBE3-HEXA-RBE3) and CWELD constraint. In order to evaluate the effects, three main NVH analyses are chosen for this study. In the first place, a free-free modal analysis is performed for the BIW and trimmed body models of a D-segment saloon car in order to estimate natural frequencies and mode shapes. Afterwards, a frequency response analysis is performed to evaluate the dynamic stiffness of engine mount. Finally, a noise transfer function (NTF) simulation is carried out to calculate the sound pressure level at driver ear's location. The out coming results from each type of simulations are extracted and compared to investigate the effect of spot-weld modeling on the accuracy of FEM analyses results concerning NVH problems.
Technical Paper
2014-04-01
Ould Mohamed Lemine Yahya, Houssem Eddine Miled
Abstract The ultrasonic (US) welding of wires in automotive harnesses is increasingly used as an alternative to mechanical splices. However, this welding process may harm the electrical terminals crimped on the wires ends as a result on the energy propagation along the wire up the terminal with a frequency that is close to the terminals' natural frequencies. The modeling of the ultrasonic welding had been investigated by several authors from the process and weld strength perspective but the modeling of its effect on electrical terminals in automotive harnesses has not been given much attention in the literature. This paper describes and illustrates approaches used for modeling of the impact of the US welding on the electrical terminals in terms of stress and deformation from qualitative and quantitative perspectives and the related benefits/limitations from predictive standpoint. Illustrations are given on an actual terminal with respect to a typical ultrasonic welding process.
Technical Paper
2014-04-01
Ramya Natarajan, Ganesan Swaminathan, Shanmugasundaram Ramanathan
Abstract The machine breakdown occurrences in the shop floor of the manufacturing facilities of Ashok Leyland, were captured into the Enterprise Resource Planning (ERP) system with significant time delay. This affected the overall productivity of the shop floor lines. Hence, there was a need to deploy a computer based application with a simple Graphical User Interface (GUI) in the shop floor, to capture breakdown and update the ERP system accordingly. This application was meant for use by the shop floor associates, who come to know of the machine breakdown occurrences first. Also, there was a need for the managers at various levels to monitor the breakdowns, to ensure their timely closure. To fulfil these requirements, the in-house IT resources were sought after by the plant maintenance group. Free and Open Source Software (FOSS) was identified for application development and deployment. FOSS aids in significant cost savings, as there is no license cost involved in application development.
Technical Paper
2014-04-01
Yaamini Devi Loganathan, Jayakrishnan M
Abstract The automobile industry in India has long been recognized as a core manufacturing sector with the potential to drive national economic growth. India's attraction as a destination for automobile manufacturers has been underscored by the number of new manufacturers entering the country over the last two decades, through FDI. The number of manufacturers has continued to grow in India over the years across vehicle segments. Multinational and Transnational firms may enter a market by different modes of Foreign Direct Investment (FDI), either by Greenfield, Mergers & Acquisitions, Joint Ventures or Contract manufacturing. Indian automobile industry currently has a wide mix of home grown automobile companies and foreign invested companies. In this FDI development and the inclusion of more automobile manufacturers, the product development process of companies also has gone through a change. The cross pollination of product development process has happened between the automobile manufacturing firms.
Technical Paper
2014-04-01
Bert Bras, Andrew Carlile, Thomas Niemann, Sherry Mueller, Hyung Chul Kim, Timothy Wallington, Heidi McKenzie, Susan Rokosz
Abstract Tools are now publicly available that can potentially help a company assess the impact of its water use and risks in relation to their global operations and supply chains. In this paper we describe a comparative analysis of two publicly available tools, specifically the WWF/DEG Water Risk Filter and the WBCSD Global Water Tool that are used to measure the water impact and risk indicators for industrial facilities. By analyzing the risk assessments calculated by these tools for different scenarios that include varying facilities from different industries, one can better gauge the similarities and differences between these water strategy tools. Several scenarios were evaluated using the water tools, and the results are compared and contrasted. As will be shown, the results can vary significantly.
Technical Paper
2014-04-01
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai, Hongzhang Cen
Abstract This paper presents a three-dimensional electrochemical electrode plate pair model to study the effect of the electrode tabs configuration. Understanding the distribution of current density, potential and heat generation rate is critical for designing li-ion batteries and conducting effective design optimization studies. We developed several electrode plate pair models which were different in position and size of tabs. Results showed the influence and comparison of different configuration on the distribution of current density, potential density and heat generation rate at different discharge process. The distribution was predicted as a function of tabs. It can provide a theoretical basis for improving battery thermal performance and cooling system design.
Technical Paper
2014-04-01
Patrick Garcia, Sandro Paparelli
Abstract and Introduction After having successfully implemented Lean in Tenneco's Clean Air division, Tenneco Europe decided to expand Lean to its other divisions - Ride Performance including Aftermarket in 2011. These divisions were able to fully benefit from the best practices developed over the last 10 years. The implementation was articulated around two major axes: the execution of complex projects related to processes including several functions and sites. This approach allowed us to reach a critical mass in a reasonable time within the different functions and sites; the execution of smaller projects focused on one specific function,e.g.: Engineering or Sales. This approach is complementary to the first one since it enhances the spread of the lean spirit within the organization. This paper focuses on Tenneco's Ride Performance division and is split into two parts. Part 1 explains: the different steps required to implement the lean mindset; the challenges to implement it, i.e: the continuous improvement cycle, the enabling bureaucracy, the way of spreading the lean within an organization, the balance of top down and bottom up, the methodologies and ways of converting the benefits into concrete results.
Technical Paper
2014-04-01
Pierre Marquette, Arnaud Dereims, Michael Hugon, Guenael Esnault, Anthony Pickett, Dimitrios Karagiannis, Apostolos Gkinosatis
Abstract Today, LRI is a proven manufacturing technology for both small and large scale structures (e.g. sailboats) where, in most cases, experience and limited prototype experimentation is sufficient to get a satisfactory design. However, large scale aerospace (and other) structures require reproducible, high quality, defect free parts, with excellent mechanical performance. This requires precise control and knowledge of the preforming (draping and manufacture of the composite fabric preforms), their assembly and the resin infusion. The INFUCOMP project is a multi-disciplinary research project to develop necessary Computer Aided Engineering (CAE) tools for all stages of the LRI manufacturing process. An ambitious set of developments have been undertaken that build on existing capabilities of leading drape and infusion simulation codes available today. Currently the codes are only accurate for simple drape problems and infusion analysis of RTM parts using matched metal molds. Furthermore, full chaining of the CAE solution will allow results from materials modeling, drape, assembly, infusion and final part mechanical performance to be used in subsequent analyses.
Technical Paper
2014-04-01
Jianghui Mao, Sayed Nassar
Abstract In this paper, experimental study and FEA simulation are performed to investigate the effect of three different methods for joining dissimilar metal coupons in terms of their strength and load transferring capacity. The joining techniques considered include adhesive bonding, bolting and hybrid bolting-and-bonding. Elastic-plastic material model with damage consideration is used for each of the joint components. Traction-separation rule and failure criterion is defined for adhesive. Load transfer capacity and the failure mode are assessed for each type of joining. Joint strength is examined in terms of the effects of adhesive property, bolt preload level, and friction coefficient. Results show that load transferred and failure mechanism vary significantly between samples with different joint methods; preload evolution in bolt changes with friction coefficient; hybrid joint generally has advantage over the other two methods, namely, bolting-only and bonding-only. With appropriate damage model, the FEA could successfully simulate the actual failure mode of the single slap joint samples.
Technical Paper
2014-04-01
Peter J. Ulintz
Abstract The application of advanced high-strength steels with ultimate tensile strengths of approximately 800 MPa is now well established within the automotive stamping industry. Current trends point to growth in higher strength applications with tensile strengths exceeding 1200 MPa. Due to their higher strength and greater springback after forming, producing high-strength steel stampings and their tools requires special attention. Effective processing methods are required that address problems specific to these materials, including: selection of an optimum stamping process and related equipment, solving formability problems, controlling springback, and selecting appropriate die steels and coatings for optimal tool life. As automakers strive to meet 2025 CAFÉ requirements of 54.5 miles per gallon, the demand for higher strength steel stampings will increase among lower tier automotive suppliers. These companies tend to be contract manufacturers and tool & die shops that are well established and experienced with mild steel and high strength low alloy materials.
Technical Paper
2014-04-01
Lei Liu, Zhiheng Yang, Bo Song, Zhengwei Fan, Jianhua Jiang
Ti-alloy sheet is a high-modulus elastic-plastic material, about which the resilience in the cold-forming process is quite difficult to control. As a matter of fact, the procedure of cold-forming is composed of many cases such as tensile case and bending case. An expression of ultimate radius for bending-curvature is obtained based on tri-parameters elastic-plastic constitutive model. By classifying the cold-forming process, some typical cases of cold-forming are presented in this paper, and analytical solutions with a high precision of resilience for high-modulus elastic-plastic material such as Ti-alloy sheet under the different typical cases are obtained in this paper. The accurate analytical solutions of resilience for high-modulus elastic-plastic material presented in this paper will contribute to cold-forming process both in the mould-designing and optimizing of cold-forming procedure.
Technical Paper
2014-04-01
Prabath Arachchige, Mohamed Abderrahmane, Ana M. Djuric
Path planning and re-planning for serial 6 degree of freedom (DOF) robotic systems is challenging due to complex kinematic structure and application conditions which affects the robot's tool frame position, orientation and singularity avoidance. These three characteristics represent the key elements for production planning and layout design of the automated manufacturing systems. The robot trajectory represents series of connected points in 3D space. Each point is defined with its position and orientation related to the robot's base frames or predefined user frame. The robot will move from point to point using the desired motion type (linear, arc, or joint). The trajectory planning requires first to check if robot can reach the selected part(s). This can be simply done by placing the part(s) inside the robot's work envelope. The robot's work envelope represents a set of all robots' reachable points without considering their orientation. To visualize the robot's work envelope many available tools can be used.
Technical Paper
2014-04-01
Fengzhu LI, Shunan Bao, Sijun LI
Lean logistics is an application of lean manufacturing principles. The core of lean logistics is to eliminate all non-value-added activities (waste) within productions, movements and storages. It reduces lead time, cuts cost, and improves quality. In order to be competitive, enterprises in western countries widely use lean manufacturing and logistics principles in automotive industries, especially for engine manufacturing system due to its high contents of assembly work. However, in China, lean logistics and its applications are fairly new to many companies. This article analyzes the current status of lean logistics in engine manufacturing in China, summarizes lean logistics principles, put forwards application of lean logistics principles based on a real case study of a new manufacturing system planning. In details, origins of the lean logistics are introduced, characteristics of engine manufacturing logistics are outlined, requirements of the lean logistics system are proposed, PFEP (Plan for Every Part) methodology is used, and packaging specifications are analyzed.
Technical Paper
2014-04-01
Vijitashwa Pandey, Zissimos Mourelatos, Matthew Castanier
Implications of decision analysis (DA) on engineering design are important and well-documented. However, widespread adoption has not occurred. To that end, the authors recently proposed decision topologies (DT) as a visual method for representing decision situations and proved that they are entirely consistent with normative decision analysis. This paper addresses the practical issue of assessing the DTs of a designer using their responses. As in classical DA, this step is critical to encoding the DA's preferences so that further analysis and mathematical optimization can be performed on the correct set of preferences. We show how multi-attribute DTs can be directly assessed from DM responses. Furthermore, we show that preferences under uncertainty can be trivially incorporated and that topologies can be constructed using single attribute topologies similarly to multi-linear functions in utility analysis. This incremental construction simplifies the process of topology construction. The methods are demonstrated using a design decision making problem of a welded beam.
Technical Paper
2014-04-01
Abhinav Karanam, Vishank Kumar, Lukas Bichler
Zirconium dioxide (ZrO2) doped with Yttria exhibits superplastic behaviour, corrosion resistance and excellent ion conducting properties [1] at moderate temperatures and thus it can be used as an electroceramic to measure the pH of high temperature water used in fuel cells. Several fabrication processes are available for preparation of zirconia ceramics. This research focused on the study of using Spark Plasma Sintering (SPS) process to prepare Yttria Stabilized Zirconia (YSZ) ceramic. 8 mol% YSZ was subjected to varying SPS sintering conditions. Samples were sintered by changing the heating cycle, dwell time, sintering pressure and cooling cycle. Subsequently, these parameters were related to the densification characteristics of the as-sintered YSZ. The results of specific gravity measurements and microstructure evaluation suggest that stepped heating followed by a slow cooling results in YSZ with highest relative density (99.9%).
Technical Paper
2014-04-01
Catherine Amodeo, Jwo Pan
The failure modes of gas metal arc welds in notched lap-shear specimens of high strength low alloy (HSLA) steel are investigated. Notched lap-shear specimens of gas metal arc welds were first made. Quasi-static test results of the notched lap-shear specimens showed two failure locations for the welds. The specimens cut from coupons with shorter weld lengths failed near the weld root whereas the specimens cut from coupons with longer weld lengths failed near the weld toe. Micro-hardness tests were conducted in order to provide an assessment of the mechanical properties of the base metal, the heat affected zone, and the weld metal. In order to understand the failure modes of these welds, finite element models were developed with the geometric characteristics of the weld metals and heat affected zones designed to match those of the micrographs of the cross sections for the long and short welds. Three-dimensional finite element analyses were conducted with consideration of micro void nucleation and growth.
Technical Paper
2014-04-01
Yuri Hovanski, John Carsley, Blair Carlson, Susan Hartfield-Wunsch, Siva Pilli
A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.
Technical Paper
2014-04-01
Anthony Lombardi, Dimitry Sediako, C. (Ravi) Ravindran, Robert Mackay
The development of an optimized heat treatment schedule, with the aim of maximizing strength and relieving tensile residual stress, is important to prevent in-service cylinder distortion in Al alloy engine blocks containing cast-in gray iron liners. However, to effectively optimize the engine block heat treatment schedule, the current solutionizing parameters must be analyzed and compared to the as-cast condition to establish a baseline for residual stress relief. In this study, neutron diffraction was carried out to measure the residual stress along the aluminum cylinder bridge following solution heat treatment. The stresses were measured in the hoop, radial and axial orientations and compared to a previous measured as-cast (TSR) engine block. The results suggest that solution heat treatment using the current production parameters partially relieved tensile residual stress in the Al cylinder bridge, with stress relief being more effective near the bottom of the cylinder.
Technical Paper
2014-04-01
Jeong Kyun Hong, Thomas Forte
Weld fatigue evaluation using the mesh-insensitive Battelle structural stress method has been applied to fusion welds, resistance spot welds and non-welded components. The effectiveness of the Battelle structural stress procedure has been demonstrated in a series of earlier publications for welded structures with different joint types, plate thicknesses, and loading modes. In this paper, a weld fatigue evaluation procedure using the Battelle structural stress method is proposed for friction stir welds currently being used in the automotive and aerospace industries. The applicability of the Battelle structural stress procedure is demonstrated by comparing fatigue life predictions for friction stir welded specimens to well-documented test data from the literature. Different specimen types, plate thicknesses and loading ratios were analyzed for several aluminum alloys. Based on this investigation, a FE based fatigue evaluation procedure for fiction stir welds is established and a master S-N design curve for friction stir welds is constructed.
Technical Paper
2014-04-01
Nia R. Harrison, S. George Luckey
This work demonstrates the feasibility of hot stamping a B-pillar outer panel from aluminum alloy 7075. AA7075 is characterized by a high strength to weight ratio with yield strengths comparable to those of DP and TRIP advanced high strength steels. Applications using AA7075 have typically been limited to the aerospace industry due to the high variable cost associated with forming and joining of these materials. A primary key to implementation in the automotive industry is the development of metal forming methods that produce non-compromised stamped parts at automotive manufacturing volumes and costs. This work explores the feasibility of die quenching a hot blank within a cold die as a means of delivering high strength aluminum sheet parts. A die made from kirksite was used to evaluate the hot stamping process for a B-pillar outer. After the forming/quenching operation, the parts were subjected to an artificial aging process to regain the properties of the T6-temper. The results show that hot stamping, followed by an adequate artificial aging treatment, produces a high strength component with material properties equivalent to the as-received T6 properties delivered by the material sheet supplier.
Technical Paper
2014-04-01
Rendong Liu, Li Sun, Xu Wang, Li Lin, Ling Zhang, Jianping Lin
The Forming limit diagram (FLD) is a powerful tool for describing the formability of sheet materials in the automobile industry, which provides fundamental data for die design and Finite Element (FE) simulation. However, traditional FLD testing is typically conducted at quasi-static strain rates from 0.001/s to 0.01/s, which are much lower than the industrial stamping process with strain rates about 1-10/s. In this research, FLDs at various punch speeds (from 1mm/s to 100mm/s or 120mm/s) were obtained for three kinds of AHSS, Quenched and Partitioned steel, Dual Phase 980 and Dual Phase 590 and three kinds of conventional steels, Low Alloy High Strength steel, Bake Hardening steel and IF steel. The results show that FLDs at a typical industrial stamping speed (100mm/s or 120mm/s) are considerably lower than the quasi-static test speed for the Advanced High Strength Steels (AHSS). It is suggested that standard Nakazima test or other formability test should be performed at 1-10/s strain rates in order to obtain the experimental data more close to industrial stamping state, especially for AHSS.
Technical Paper
2014-04-01
Gang Huang, Sriram Sadagopan, Hubert Schreier
Forming limit curve (FLC) and fracture forming limit curve (FFLC) are valuable tools for failure prediction in forming simulation and die try-out in press shops. In this paper, methods are presented to determine FLC and FFLC for sheets of advanced high strength steels (AHSS) using digital image correlation (DIC). Dome tests were conducted on AHSS specimens using DIC system for strain measurement. For generating FLCs, two approaches are introduced to determine the onset of localized necking by analyzing the strain history at critical locations, one of which has been implemented into the commercial DIC software Vic-3D (Correlated Solution inc.). For determination of FFLC, a method for measuring fracture strains based on the strain path evolution is presented. The measured FLCs for several AHSS were compared to the FLCs using ISO 12004-2, and conventional North American experimental measurements and empirical equations. The results of comparison revealed that FLCs using DIC are in good correlation with other existing data, thus validating the presented methodologies.
Technical Paper
2014-04-01
Jianghui Mao, Carlos Engler-Pinto, Xuming Su, Scott Kenningley
In this paper, the cyclic deformation behavior of an Al-Si-Cu alloy is studied under strain-controlled thermo-mechanical loading. Tests are carried out at temperatures from 20 °C to 440 °C. The effect of strain rate, hold time at temperature and loading sequence are investigated at each temperature. The results show that temperature has a significant effect on the cyclic deformation of Al-Si-Cu alloys. With increasing temperature, the effect of strain rate and hold time become more significant, while load sequence effects remain negligible within the investigated temperature range. Thus, an elasto-viscoplastic model is required for modeling the alloy's behavior at high temperature. This study provides an insight into the necessary information required for modeling of automotive engine components operating at elevated temperature.
Technical Paper
2014-04-01
Guowu Shen, Su Xu, Jie Liang, John Sollen
Magnesium alloys are of growing research, development and commercial interest for their lightweight characteristics, notably in the automotive sector. Recent results based on experiments and simulations of beam components have shown that finite element (FE) predictions using commercial FE software may significantly overestimate the peak load and load beyond the peak load. This indicates that better deformation and failure criteria are needed for crashworthiness simulation and design of Mg alloys for the development of computer-assisted engineering (CAE) capacity for Mg alloys. In this study, yield and hardening laws for deformation simulation of Mg alloys are reviewed. An isotropic Lode angle dependent von Mises yield and flow model originally used for soil was modified by replacing shear strength with tensile or compressive flow strength for deformation simulation of Mg alloys. In this law, the yield and strain hardening criteria depend on Lode angle (θ), a parameter related to the stress state of the material, e.g. θ=0corresponds to uniaxial tension and θ=30° corresponds to pure shear.
Technical Paper
2014-04-01
Li Huang, John V. Lasecki, Haiding Guo, Xuming Su
In present paper, the process of joining aluminum alloy 6111T4 and steel HSLA340 sheets by self-piercing riveting (SPR) is studied. The rivet material properties were obtained by inverse modeling approach. Element erosion technique was adopted in the LS-DYNA/explicit analysis for the separation of upper sheet before the rivet penetrates into lower sheet. Maximum shear strain criterion was implemented for material failure after comparing several classic fracture criteria. LS-DYNA/implicit was used for springback analysis following the explicit riveting simulation. Large compressive residual stress was observed near frequent fatigue crack initiation sites, both around vicinity of middle inner wall of rivet shank and upper 6111T4 sheet.
Viewing 241 to 270 of 19605

Filter

  • Article
    1234
  • Book
    54
  • Collection
    12
  • Magazine
    798
  • Technical Paper
    8351
  • Standard
    9156
  • Article
    9156