SIMULIA Resource Center

Customer Papers

Thermoplastic materials are inherently nonlinear in their deformation and temperature behavior. These nonlinearities can present significant challenges when performing finite element analyses during product design or failure analysis. In this study we have shown how an advanced user-material model (UMAT) can be calibrated and used to simulate the behavior of polycarbonate (PC) at temperatures from -30°C to +90°C. The calibration was performed using experimental data from both uniaxial tension at different temperatures, and uniaxial creep at different stress levels. The techniques and software tools used for the material model development and calibration procedure will be presented in detail illustrating also how the analysis strategy can be applied to other materials.

Customer Papers

Most automated material fitting procedures in commercial FEA codes assume that “ideal tests” are used to generate measured material data. Unfortunately, there are many scenarios where only “non-ideal” test data are available. This paper presents two case studies that highlight various strategies to transform and/or salvage such distorted test data so that viable FEA material representations can be created. Two examples are presented: (1) The hyperelastic characterization of a nearly incompressible elastomer that is manufactured with a stiff PET film on one side which prohibits the use of planar shear testing and distorts data from puck compression testing and (2) The characterization of nearly incompressible elastomers reinforced by short stiff fibers.

Customer Papers

Abaqus simulation tools have been a critical part of the development of the Michelin Tweel tire structure. A design process has been built around Abaqus 2D and 3D simulations using both Abaqus/Standard and Abaqus/Explicit solvers. This process has allowed Michelin Tweel tire designers to quickly optimize new Tweel tire dimensions for stiffness, contact pressure, durability, and rolling dynamics. The available Python Scripting Interface and Fox Toolkit have allowed for elements of the process to be simplified into easy-to-use tools that help reduce the burden of building ready-to-run models and post processing results. This paper will outline this design process with emphasis on modeling techniques and the Python based tools.

Customer Papers

The milling process is one of the most common metal removal operations. It is widely used in a variety of manufacturing industries including the aerospace and automotive sectors. Intense international competition has focused the attention of manufacturers on automation as means to increase productivity and improve quality. Modeling and simulation of cutting processes have the potential for improving cutting tool designs and selecting optimum conditions, especially in advanced applications such as high-speed milling. The objective of this study was to develop a methodology for simulating the cutting process in end milling operation to predict tool, and workpiece stresses and temperatures using 3D finite element analysis with Abaqus/Explicit.

Customer Papers

The integrity of the nuclear reactor core barrel and its components is one of the most critical issues of the reactor pressure vessel internals due to the unacceptable consequences of their failure and due to the difficulty of their replacement. Especially for such components thermal fatigue is one of the significant long-term degradation mechanisms, due to the fact that thermal loadings lead to most fatigue relevant stresses and strains.

Customer Papers

A general computational approach for modeling of damage in heterogeneous materials and structures under dynamic load is the focus of the current work. The approach covers processes of both damage initiation and damage propagation. In addition, multiple damage modes are considered to capture complex mechanisms of material failure. The proposed approach is based on selection of two types of expected damage mechanisms, namely, interfacial and internal damage.

Customer Papers

Gas Metal Arc Welding (GMAW) process is being widely used in the automotive torque converter assembly line for joining and sealing purposes. This paper describes the modeling and simulation of the welding process using the finite element modeling technique. The commercial finite element program ABAQUS/Standard is used to model the 3D thermo-mechanical coupling of the process.

Customer Papers

The large deformation finite element analysis such as metal forming analysis usually involves processes to deform, stamp, or punch a part drastically, which causes great changes in shape of the part during the simulation. As the part is reshaped, the mesh elements are deformed, and element shape quality is decaying as analysis continues. To resolve this problem, it is common to adaptively remesh the part during the analysis to replace the unusable mesh with a new better quality mesh. The proposed method is an alternative adaptive remeshing method, which not only locally refines the mesh around the areas that are likely to experience large deformation, but also adjusts the mesh directionality and anisotropy to reduce the severity of element distortion as analysis continues.

Customer Papers

We present a finite element model which takes into account the dynamic interaction between a truck and the bridge over which it is passing. The truck-bridge system presented by Marchesiello (1999) and also used by Zhu (2002) is employed to verify our model. The vehicle is a 3D truck with seven degrees of freedom. The bridge is a continuous three-span slab.

Customer Papers

The use of iSight to automate Inergy's simulations related to automotive plastic fuel tank development is highlighted by three examples: 1. the static venting simulation, where the low added value part (finding the position of valves on the tank so that the customer's specifications are fulfilled) is automated. This allows the expert to focus on higher added value tasks. 2. the tank aging simulation, which consists in computing the permanent deformation of the fuel tank caused by the plastic creep. ISight permits to easily investigate different tank architectures at early stage of development. 3. the blow molding simulation is simplified so that non-simulation specialists are able to run it. This eases the access to simulation for technical experts.

Customer Papers

A time-independent constitutive model for HY-80 (High Yield) steels with a yield plateau is outlined. The model couples the non-linear kinematic hardening concept with a memory surface in the plastic strain space, to account for progressive cyclic hardening/softening, and a pseudo memory surface in the deviatoric stress space, to correctly describe the plateau response. The model is incorporated into Abaqus/Standard through a UMAT. The performance of the model is validated against experimental data.

Customer Papers