Invited Presentation:

An Object Oriented Approach to the Finite Element Analysis and Design of Material Processes

Nicholas Zabaras
Sibley School of Mechanical and Aerospace Engr.,
188 Frank H. T. Rhodes Hall,
Cornell University,
Ithaca, NY 14853-3801, USA
Email: mailto:%20zabaras@sofia.mae.cornell.edu

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Abstract

An approach to the computational analysis and design of material processes using classes, inheritance and virtual functions allows a very fast and robust implementation of various processes, materials and design objectives as well as development and testing of various mathematical models and algorithms.

At the first part of the presentation, an object oriented Lagrangian FEM analysis of metal forming processes will be briefly presented. Examples of the classes developed to represent the various physical aspects of such processes (e.g. constitutive behavior, large deformation kinematics, contact and friction conditions, etc.) will be given. A similar simulator has also been developed for a continuum sensitivity analysis of forming processes with respect to preform and die surfaces, process conditions and other. It will be shown how the direct and sensitivity simulators can be coupled within an object oriented environment in order to produce simulators for the design of forming processes.

In the second part of this presentation, an object oriented environment for the analysis of directional solidification and crystal growth processes will be briefly reviewed. For such processes, we developed and independently tested classes for each transport mechanism as well as for electromagnetic stirring and phase change. Two additional simulators were also developed for the calculation of continuum sensitivity and adjoint fields. Such fields are necessary for an infinite dimensional design and control of solidification processes. We are particularly interested to calculate the boundary mold/furnace cooling/heating conditions in order to obtain a stable desired growth with given freezing front heat flux conditions (i.e. given microstructure). Finite element implementation of such design/control problems will be shown to be ideally suited to an object oriented approach.

Finally, some remarks on the efficiency and accuracy of object oriented FEM implementations for large scale materials processing analysis and design will be given.