Improved Dynamic Optimization Method for Uncertain Structures with Interval Parameters

An improved interval dynamic optimization method is presented for uncertain structures with interval parameters. Due to the complexity of the interval optimization problem,it is transformed into an approximate deterministic one through optimizing the upper bound of the structural interval response.To obtain more accurate interval value of the structural response,the derivatives in the Taylor series expansion of the structural response are also considered to be interval.As a result,the approximate interval almost includes the exact structural response.Because mean values and uncertainties of the design variables are selected as optimization variables,more optimization information can be obtained by the interval optimization method.A typical frame structure is used to demonstrate the effectiveness of the method.Optimization results show that the proposed method can obtain the optimal design variables which are almost the same as that obtained by the traditional optimization method.Furthermore,an interval value of the objective function corresponding to the variation of the optimal design variables can be obtained.