Multiobjective and multilevel optimization for steel frames

A new application of multiobjective and multilevel optimization techniques for steel frames is presented. Two levels: system and element, and two obje ctives: maximization of the total structural strain energy and minimization of the total structural weight are considered. The constraints of frequenc y, strength, buckling, displacement and variable-hounds are treated. Using the building codes, AISC-LRFD, AISC Seismic Provisions and Chinese GBJ17-88 , formal mathematical formulations are made. A demonstration example shear steel frame under gravity and earthquake loads is given. (C) 1998 Elsevier Science Ltd. All rights reserved.