单层球面网壳中响应面法的交叉项研究

Cross item of response surface method in single-layer spherical lattice shell

不考虑交叉项的二次超曲面的响应面方法常用于工程结构的可靠性分析中,但在数学上无法证明该响应面构筑是否真实.本文通过对单层球面网壳在竖向简谐荷载下可靠指标的分析,发现了给定失效指标和结构位移响应之间的关系,获得了是否需要考虑交叉项进行可靠性分析的量化指标.

The secondary-hypersurface in response surface method without considering its cross item is commonly used in describing structural reliability, but the truth of above mentioned surface can not be proved in mathematics. The reliability index of single-layer spherical shell under the vertical harmonic load are studied in the paper. The relationship between structural displacement and the failure index is obtained. Finally, the quantitative ratio of displacement to failure index is suggested, by which we can determine if the consideration of the cross item in the secondary-hypersurface is necessary.