An uncertain structural optimization method based on interval description of uncertainty

In this paper, an uncertain optimization method is suggested to solve the uncertain structural problems based on the nonlinear interval number programming and the interval analysis method. Through the order relation of the interval numbers, the uncertain objective function is transformed into two deterministic objective functions. For each specific design vector, the interval analysis method is applied to compute the interval of the objective function efficiently and whereby the optimization nesting can be eliminated. An unconstraint scalar objective function is then obtained through linear combination method of the multi-objective problem and penalty function method. The presented method is applied to an automobile frame with uncertain material property.