ABAQUS finite element code

Some advanced general purpose finite-element codes, well adapted for stress analysis in particular, e.g. ABAQUS or MSC.MARC, have certain capabilities to simulate the stress-assisted diffusion, too. Unfortunately, they still are limited in some rather important aspects. As regards ABAQUS, this allows to perform simulations of the stress-assisted diffusion governed by equation (5) "over" the data of an accomplished solution of a geometrically and physically nonlinear stress-strain analysis, i.e., for the stationary stress field at the end of some preliminary loading trajectory, but not for the case of simultaneous transient loading and hydrogenation. 

The AECL team used an in-house MOTIF finite-element code (Guvanasen and Chan 2000), which is based on an extension of the classical poroelastic theory of Biot (1941). This code has undergone extensive verification and validation (Chan et al. 2003). The CTH team employed the commercially available, general-purpose finite-element code ABAQUS/Standard 6.3 (ABAQUS manuals). This code adopts a macroscopic thermodynamic approach. The porous medium is considered as a multiphase material, and an effective stress principle is used to describe its behaviour. ABAQUS allows the value of bulk modulus of the mineral grains as an input parameter. In order to select an appropriate value for this low-permeability, low-porosity rock, the CTH team compared the ABACjus solution with Biot s (1941) analytical solution for ID consolidation in the form presented by Chan et al. 2003). 

The new procedure is developed using a general purpose finite element code, ABAQUS (Abaqus,... 

The nonlinear constitutive models used in this study are the so-called pseudo stress and pseudo strain models of Schapery [49]. They were quite easily implemented and the former yielded a reasonable representation of the rubber used in this work. The time-dependent, finite strain constitutive model from the finite element code, ABAQUS, was also used in this study. 

Many commercial finite element computer programs (for example ABAQUS, ADINA, ANSYS, DYNA, DYNA3D, LS-DYNA, NASTRAN and NONSAP) arc readily available for nonlinear dynamic analysis. Other computer codes, such as CBARCS, COSMOS/M, STABLE, ANSR 1 have been developed specifically for the design of structures to resist blast toads. All these computer programs possess nonlinear analysis capabilities to varying degrees. 

Stress calculations are carried out by the finite element method. Here, the commercial finite method code ABAQUS (Hibbit, Karlsson, and Sorensen, Inc.) is used. Other codes such as MARC, ANSYS are also available. To calculate the stresses precisely, appropriate meshes and elements have to be used. 2D and shell meshes are not enough to figure out stress states of SOFC cells precisely, and thus 3D meshes is suitable for the stress calculation. Since the division of a model into individual tetrahedral sometimes faces difficulties of visualization and could easily lead to errors in numbering, eight-comered brick elements are convenient for the use. The element type used for the stress simulation here is three-dimensional solid elements of an 8-node linear brick. In the coupled calculation between the thermo-fluid calculation and the stress calculation a same mesh model have to be used. Consequently same discrete 3D meshes used for the thermo-fluid analysis are employed for the stress calculation. Using ABAQUS, the deformations and stresses in a material under a load are calculated. Besides this treatment, the initial and final conditions of models can be set as the boundary conditions and the structural change can thus be treated. 

ABAQUS (2000). Finite Element Analysis Code and Theory (Standard and CAE),... 

Four research teams—AECB, CLAY, KIPH and LBNL—studied the task with different computational models. The computer codes applied to the task were ROCMAS, FRACON, THAMES and ABAQUS-CLAY. All of them were based on the finite-element method (FEM). Figure 6 presents an overview of the geometry and the boundary conditions of respective models, including the nearfield rock, bentonite buffer, concrete lid, and heater. The LBNL model is the largest and explicitly includes nearby drifts as well as three main fractures... 

The Finite Element Method (FEM) is used to analyze the indentation process. All cases have been analyzed by the Finite Element Method (FEM) using a general purpose code of implicit methodology (ABAQUS/Standard) [8]. 

Non-linear finite-element models of high damping rubber bearings have been developed and implemented in the ABAQUS code in the framework of Italian cooperative studies for seismic isolation development. The Hyperelastic models used have been based on the results of tests on rubber specimens. The isolators models are validated through comparison of numerical results with complete bearing test data. 

Furthermore, Liu et al. (2008) proposed a general finite element method solution that enables dynamically fast simulation of deformation on the newly available GPU hardware with CUD-A. Their test results indicate that the GPU with CUDA enables an increase speed of approximately four times for FEM deformation computation on an Intel(R) Core 2 Quad 2.0 GHz machine with GeForce 8800 GTX. Many commercial finite element analysis codes, e.g., ABAQUS, MSC. MARC, and ANSYS, have released their own GPU-based versions. The performance studies demonstrate that the GPU results in speedups in the range of 3-6 times. 

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