This study develops two new indices in structural optimization to minimize peak response and settling time of free vibration, respectively. The two new indices are developed by substituting weight functions into a classic quadratic integral index. With the weight functions, the contributions of structural responses in different time intervals to the value of performance index can be adjusted according to requirements. In such a way, the new indices can approximately evaluate structural performances in reduction of the peak response and settling time, respectively. The new indices have the advantages that they retain the benefits of the classical index for the ease of numerical calculation and sensitivity analysis. Furthermore, they are easy to implement by slightly modifying various developed optimization approaches. Finally, four numerical examples are considered. The proposed two new indices show good performance in reducing the peak response and settling time of free vibration.
Free vibration, Structural optimization, Settling time, Peak dynamic response