A KNOWLEDGE-BASED SYSTEM FOR GENERATION AND CONTROL OF FINITE-ELEMENT MESHES IN FORGING SIMULATION

This article presents a two-dimensional mesh generation system designed to generate all quadrilateral meshes for forging applications. The system splits the meshing geometry into a set of "primitives" using a knowledge-based system. It further splits these primitives into quadrilaterals using standard primitive splitting algorithms and meshes each quadrilateral using parametric mapping. Reasons for choosing this approach are explained, followed by a brief description of the implementation procedures. Three mapping techniques-namely, two-dimensional Lagrange interpolation, two-dimensional Hermite interpolation, and numerical solution of Poisson's equation-were tested for their applicability to forging problems. This article provides a comparison of the three mapping techniques in terms of mesh quality and computational time. Finally, it presents results of three forging simulations that demonstrate the effects of element distortion on finite-element solutions of large plastic deformation problems and points out the correlation between distortion parameters such as skew and taper and the solution accuracy.