Abstract
This paper presents an efficient optimal earthquake-resistant design method for truss structures. The optimum design method is developed by using convex and separable approximation concept, dual method, discrete-sensitivity analysis and suboptimization techniques. The coordinates of panel points, cross-sectional dimensions and discrete material kinds of all member elements are dealt with as the design variables. Constraints on stresses and displacements caused by static and earthquake loads and constraints on slenderness ratio are considered, respectively, as behavior and side constraints. The behaviors and their sensitivities due to earthquake motions are calculated, respectively, by the response spectrum analysis method and the Nelson's method. As the design examples the cost minimization problems of 193-bar transmission tower are shown for the three design conditions with different unit costs of land of construction sites. By comparing the optimum solutions, the rigorousness, efficiency and reliability of the optimum design method are demonstrated.
