Abstract
The optimum elastic and plastic design methods of plane rigid frames have been proposed in many previous studies. But, they have not dealt with the ootimum design problem considering elastic constraints and plastic constraints simultaneously. In this paper, first, the limit analysis method is presented considering the axial force-bending moment interaction vield condition. Next, the optimum design method is suggested, in which the minimum weight design of a structure is obtained under the simultaneous constraints of elastic stresses, elastic story drift angles, plastic faqilure load factors and the strength ratios of column-to-beam. And, solving the optimum plastic design problem of a portal frame and the optimum elastic and plastic design problem of a 12 story frame, It is confirmed that this method gives the optimum design solution.
