Optimal Synthesis of Frameworks under Elastic and Plastic Performance Constraints Using Discrete Sections

ABSTRACT A computer-based method is presented for minimum-weight design of planar frameworks under service and ultimate performance conditions using discrete member sections. Service-load conditions ensure acceptable elastic stresses and displacements, and ultimate-load conditions ensure adequate safety against plastic collapse. The sizes of the discrete sections, which can be of any type; e.g., WF, HSS, etc., may be constrained to satisfy fabrication requirements related to member continuity and structure symmetry. The design method is iterative in nature and remarkably efficient. The number of iterations is generally small and almost totally independent of the complexity of the structure. Several comparative designs for simple truss and frame structures are presented to illustrate features of the method.