An Approach To Structural Optimization—Sequential Quadratic Programming, Sqp

On the basis of previous works, here we propose an approach to the optimal design of engineering structures for member sizing and shape optimization. This approach is based on the transformation of a non-linear programming problem (NLP) into a sequence of quadratic programming problems (SQP). Compared with the commonly used sequential linear programming (SLP), SQP is more suited to the highly non-linear problems of structural optimization. Different modes of SQP may be used. Four types of SQP presented in this paper have been demonstrated to be stable and rapid in their convergence according to our experiences. Quadratic programming (QP) has several reliable and efficient algorithms for its solution which require more computation than does linear programming, but owing to the reduced number of iterations in optimization, the total work involved in SQP is in general less than that of SLP. Further developments of SQP will be very helpful for structural optimization.