Abstract:In this paper, a support system of optimum aseismic design is proposed on the basis of fuzzy set theory and a graphical representation method. In optimum aseismic design of buildings, it is necessary to take account of subjective evaluation of users. In this system, a hierarchical model is employed to idealize and model the decision process of optimum aseismic design. By applying fuzzy set theory, this system can take account of subjective evaluation of users. The system is a prototype of an expert system for optimum aseismic design, and its knowledge is compiled interactively as numerical values by the fuzzy confluence rule and membership functions in fuzzy set theory in accordance with the hierarchical model given by users. Knowledge, which is necessary to perform the inference on optimum aseismic design, is acquired interactively. Optimization is performed by fuzzy multiobjective maximizing decision, and the maximum evaluation values of the top attribute can be found. Furthermore, distributions of the grade of membership value in maximizing the decision process are graphically represented, so the user can understand this process easily and intuitively. A case study is carried out for a reinforced concrete typical high school building in Kobe City.