RELIABILITY-BASED OPTIMIZATION DESIGN METHOD OF STRUCTURAL SYSTEM USING INFORMATION INTEGRATION METHOD

In this study, an optimization method of a structural system is proposed using the Information Integration Model (IIM) and Genetic Algorithm (GA). Structural design should be performed so that the structural system satisfies various requirements, for example, safety, economic and social requirements, etc. Therefore, the general design problem of a structural system should be formulated as a multi-objective optimum design problem with multi-constraint conditions. In such a design problem, evaluation of the system with respect to various evaluation items is necessary. However, the formulation and calculation of such evaluations are difficult, because each of the evaluation results corresponding to various evaluation items has other dimensions. To overcome these difficulties, this study uses the IIM to evaluate at what level the system satisfies all the evaluation items. The IIM is a powerful calculation method of system evaluation. Moreover, formulation and calculation are easy by making use of the IIM. Therefore, simple mathematical programming techniques can be used for system optimization. This study uses the GA as an optimization method. For a numerical example, an optimum design problem of a highway bridge girder is considered. Results obtained by this method are compared with those of the present design method, and then the efficiency of this method is demonstrated.