Abstract:

This paper presents a new interval optimization method for the multi-story frame structure with uncertain design parameters. In the proposed method, the uncertain design parameters are characterized as intervals, and the interval optimization problem is transformed into an approximate deterministic one by optimizing the upper bound of the structural interval response. A typical four-story frame structure is then used to perform the interval optimization with frequency constraint. The results show that the proposed interval optimization method may result in optimal design parameters similar to that obtained by the conventional method and may help to obtain the variation range of structural response due to the small variation of optimal design parameters, thus laying theoretical foundations of the reliability analysis of frame structures.

Key words: frame structure, structural optimization, parameter uncertainty, interval mathematics, reliability