A system approach to solid free form design of optimal structures

Most of the work in the field of topology optimization is concentrated on using sensitivity analysis and optimality criteria methods that need explicit formulation. The design systems are often hard-coded for a specific problem with specialized optimization and FEM routines. This paper presents a work that uses a system approach to solid free form design. It attempts to develop a general topology optimization system that has a wide range of applicability by making use of sophisticated optimization and FEM packages available. A computer design system is implemented with an integration of commercial codes CFSQP and NASTRAN. A pre-processor and a post-processor are developed to assist the optimal design process. The system is tested with benchmark cases for minimum mean compliance and minimum weight designs. The results for the cases are presented, demonstrating the ability of the system to handle complex cases with practical feasibility. The implementation is evaluated with a parametric study of its performance. The key factors for the common problems of topology optimization are examined, including the mesh dependency and numerical instability. The computational efficiency is further studied to indicate the direction for further improvement of the system.