GENERATING OPTIMAL CONFIGURATIONS IN STRUCTURAL DESIGN USING SIMULATED ANNEALING

This paper presents a combinatorial optimization procedure based on the simulated annealing approach for generation of optimal configuration of structural members. The work is based on altering the finite element model of structure by removing or restoring elements to minimize the material use subject to constraints on maximum stress value and maintenance of connectivity between elements. Such an optimization problem is categorized as a large-scale, non-convex and non-linear problem. Thus, the problem can have multi-minima and it is important to find the global optimum solution as opposed to a local minimization. To improve the computational efficiency, the non-linear shape optimization problem has been linearized and to account for the difference between the non-linear and the linearized values a correction factor is implemented. To illustrate the approach, several design examples are presented and the effect of the parameter of the simulated annealing on the final configuration design is examined. © 1997 by John Wiley & Sons, Ltd.     

THREE-DIMENSIONAL TRANSIENT MOLD COOLING ANALYSIS BASED ON GALERKIN FINITE ELEMENT FORMULATION WITH A MATRIX-FREE CONJUGATE GRADIENT TECHNIQUE

A methodology is presented to simulate the three-dimensional heat transfer within a mold during the injection molding process. The mold cooling analysis assists cooling channel design and paves the way for part shrinkage and warpage analysis. The transient temperature distributions in the mold and the polymer part are simultaneously computed by Galerkin Finite Element Method (GFEM) using a matrix-free Jacobi Conjugate Gradient (JCG) scheme. The numerical method presented here is efficient and has shown to require a fraction of the memory and computing time required by conventional methods. The matrix-free algorithm is initially validated using an injection mold designed to produce a plaque with a molded-in hole. Subsequently, the method is further applied to a representative automotive plastic component.