FINITE ELEMENT ANALYSIS AND DESIGN OPTIMIZATION

FINITE ELEMENT ANALYSIS AND DESIGN OPTIMIZATION

ABSTRACT

The integration of optimization techniques with Finite Element Analysis (FEA) and CAD is having pronounced effects on the product design process. This integration has the power to reduce design costs by shifting the burden from the engineer to the computer. Furthermore, the mathematical rigor of a properly implemented optimization tool can add confidence to the design process. Generally, an optimization method controls series of applications, including CAD software as well as FEA automatic solid meshers and analysis processors. This combination allows for shape optimization on CAD parts or assemblies under a wide range of physical scenarios including mechanical & thermal effects.
Modern optimization methods perform shape optimizations on components generated within a choice of CAD packages. Ideally, there is seamless data exchange via direct memory transfer between the CAD and FEA applications without the need for file translation. Furthermore, if relation between the CAD and FEA software exists, any changes made in the CAD geometry are immediately reflected in the FEA model. In the approach taken by ALGOR, the design optimization process begins before the FEA model is generated. The user simply selects which dimension in the CAD model needs to be optimized and the design criterion, which may include maximum stresses, temperatures or frequencies. The analysis process appropriate for the design criteria is then performed. The results of the analysis are compared with the design criterion, and, if necessary without any human intervention, the CAD geometry is updated. Care is taken such that the FEA model is also updated using the principle of associativity, which implies that constraints and loads are preserved from the prior analysis. The new FEA model, including a new high-quality solid mesh, is now analyzed, and the results are again compared with the design criterion. This process is repeated until the design criterion is satisfied. The optimization method also allows for global constraints to enforce weight and volume criteria. These global calculations require little additional effort because of the tight integration among the applications, including the weight, center of gravity and mass moment of inertia processor. Even though global constraints can be used to optimize material usage, engineering expertise is generally required to optimize costs.