Finite Element Simulations of Joints Used in the Automotive Industry

Author(s):  
Rishikesh Bhalerao ◽  
Brad Heers ◽  
Mark Bohm ◽  
Marc Schrank

Finite element-based simulations of vehicle body systems are an effective means of optimizing a design. However, body systems often consist of components from a variety of sources. Hence, accurate modeling requires a robust set of analysis functionality for joining such components. Joints—such as welds, bolts, rivets, clinches, and adhesives—present unique challenges to the analyst. Despite the critical influence joints have on functional performance, there is little information on best practices for modeling such connections. This paper presents a survey of some of the approaches available in ABAQUS, a general-purpose commercial finite element code, and discusses various applications of these techniques through a series of case studies. While the modeling techniques discussed in this paper have been motivated largely by automotive applications, they are also applicable to other areas such as aerospace structures.

2000 ◽  
Vol 123 (4) ◽  
pp. 436-441 ◽  
Author(s):  
Guohua Zhang ◽  
Xin Wu ◽  
S. Jack Hu

In this paper, the occurrence of recoil and surface warp during the flat surface-straight edge hemming process is investigated. A general-purpose finite element code ABAQUS/Standard is used to simulate the hemming operations. Reverse bending and springback are the fundamental mechanisms that cause surface warp and recoil. Recoil and warp are not independent. One parameter, final equivalent warp, is used to represent both. Pre-hemming target ending position is proposed based on the minimization of the final equivalent warp. The influence of the geometrical and process parameters on recoil and warp are also discussed.


Author(s):  
T. Rahman ◽  
S. T. IJsselmuiden ◽  
M. M. Abdalla ◽  
E. L. Jansen

In earlier research the authors optimized variable stiffness panels for maximum buckling load, using lamination parameters. The aim of the present research is to analyze those optimized panels in the postbuckling regime so that further improvement can be achieved in the future with respect to its postbuckling performance. Because the incremental-iterative nonlinear analysis in the postbuckling regime is not feasible within an optimization loop a finite element based perturbation method (Koiter type) is used to compute postbuckling coefficients, which are in turn used to make a quick estimate of the postbuckling stiffness of the panel and to establish a reduced order model. The proposed perturbation method has been implemented in a general purpose finite element code. In the present work the postbuckling analysis of variable stiffness panels carried out using the reduced order model is presented and the potential of the approach for incorporation within the optimization process is demonstrated.


1987 ◽  
Vol 109 (1) ◽  
pp. 33-41 ◽  
Author(s):  
E. Riks

In the field of finite element structural analysis, the computation of collapse states of structures prone to unstable behavior has long been considered a difficult if not intractable problem. Only recently have procedures that deal effectively with this difficulty found their way in general-purpose finite element codes. Although the explanation for the cause of the so-called limit point obstacle is actually simple—an inappropriate parameterization of the governing equations in the neighborhood of the limit point—this cause does not seem to have been widely understood in the period of development of the finite element technique. In this paper, some of the remedies that have been proposed to overcome the problems are reviewed, including the principle of adaptive parameterization which is now the basis of a new procedure for collapse analysis in the finite element code STAGS. The discussion also includes the treatment of simple bifurcation points because unstable bifurcation can be considered a special form of collapse. It can be concluded that collapse problems, in the sense discussed in this paper, no longer present difficulties that exceed those normally encountered during the solution of nonlinear deformation paths. Further developments, in particular those with respect to improved efficiency, are in progress. Some of the promising ventures in this direction are indicated.


Author(s):  
David L. Littlefield ◽  
Kenneth C. Walls ◽  
Kent T. Danielson

In this work we have coupled the EPIC code to the LS-DYNA code to provide a high-fidelity simulation framework for simulation of blast-structure-fragmentation interaction. The coupled code exploits the strengths of the two original codes: EPIC, which has special algorithms and models for weapons effects analysis, and LS-DYNA, which is a general purpose finite element code for modeling large-scale structural deformation. Example problems are shown which illustrate the advantages of this approach.


Author(s):  
Ali Cinar

Finite element analysis has been used widely in the automotive industry to evaluate design alternatives. Especially when there is no prototype part for rig or vehicle testing, CAE (Computer Aided Engineering) is the only tool to evaluate whether the design meets its target or not. Truck chassis, 5th wheel table and its reinforcement has been modeled for stress calculations under 5th wheel forces. Various FE modeling techniques have been evaluated, including assembly loads and contact modeling, and their effect on the stress distribution has been demonstrated. The aim of this paper is to demonstrate the important parameters that effect stress distribution on the critical areas under the 5th wheel.


Author(s):  
Pranali Yogesh Kajale ◽  

Composites have proved their usefulness in the automotive industry during recent years. Many automobile companies use them in different parts to reduce weight without hampering strength. In a composite material, Lay-up sequence and orientation highly affects the properties of the laminate. Therefore, it is important to perform design optimization on a component to achieve high strength in minimum weight. This paper deals with the optimization of lay-up for composite Racing Seat using finite element analysis. Different lay-up sequences for laminates including, cross-ply [0/90]n, angle-ply [±α]n, and [0/90/±α]n are analysed. The lay-up sequence, orientation and ply number are optimized using composite material carbon fibre/Epoxy. Driver’s ergonomics and impact sustainability are considered constraints for weight optimization. Driver’s ergonomics were based on 95th percentile male and 5th percentile female rule. Force analysis is performed on the seat according to SFI 39.2 to evaluate the strength requirement. Finite element analysis of composite racing seat is performed via commercial finite element code ANSYS and using the capabilities of ANSYS Composite PrepPost (ACP) to form desired composite lay-up. A finite element code is based on classical lamination theory; including Puck’s failure criterion for first-ply failure. The seat is divided into three portions with a different number of layers considering the values and specific nature of acting forces; which resulted in different thicknesses in different regions. The optimization results show that for all the angles of Angle-ply laminate considered, Angle-ply laminates with an angle of 45⁰ provides a more optimum design. The minimum weight obtained is 10.15 kg.


2000 ◽  
Author(s):  
Ellen Zhang ◽  
Xin Wu ◽  
S. Jack Hu

Abstract In this paper, the occurrence of recoil and surface warp during flat surface-straight edge hemming process is investigated. A general-purpose finite element code ABAQUS/Standard is used to simulate the hemming operations. Reverse bending, localized buckling and springback are the fundamental mechanisms that cause surface warp and recoil. Recoil and warp are not independent. One parameter called final equivalent residual warp is obtained to represent both. Feasible pre-hem ending zone is proposed based on final equivalent residual warp. The influence of the geometrical and process parameters on recoil and warp are also investigated.


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