针对地震作用及结构性能的随机性,通过分析抗震可靠度研究结构的抗震性能,将均匀设计与响应面法相结合,提出了结构可靠度的数值模拟新方法,包括基于均匀设计的响应面法、均匀设计响应面与蒙特卡罗抽样相结合的混合模拟法.结合钢框架结构的抗震可靠度问题,基于ANSYS实现了上述新方法,并与经典的可靠度数值模拟方法进行对比分析.分析结果表明:均匀设计的偏差大约为正交设计的10%~20%;基于两者的混合模拟法的计算偏差,前者为后者的42%~85%;同时混合模拟法较蒙特卡洛法计算效率提高了480倍以上.均匀设计选取的试验点更加均匀和具有代表性,均匀设计响应面法构造的结构极限状态函数精度更高,偏差更小,同时基于均匀设计响应面的混合模拟法不仅精度高,还可以大大提高计算效率.
There exist randomness both in earthquake actions and in structural performance;therefore,the seismic reliability analysis of structures should be done to assess seismic performance of structures.Two new numerical simulation methods for structural reliability analysis are proposed,which include uniform design response surface method(UDRSM),and hybrid simulation method(HSM) combing Monte Carlo Simulation(MCS) and UDRSM.Theses methods are all implemented in ANSYS by using deterministic finite element method.The new two methods are then applied to seismic reliability analysis of steel frame structures.The accuracy and efficiency of the new methods are demonstrated by contrasting the new methods with the classical numerical simulation methods including Monte Carlo simulation(MCS) and orthogonal design response surface method(ODRSM).The results indicate that difference of UD is 10%-20% of that of OD;The calculation difference of hybrid simulation method based on UD is 42%-85% of the method based on OD;Computing efficiency of hybrid simulation method is more than 480 times of Monte Carlo Simulation.It is found through the numerical example that the experiment points chosen by uniform design are more uniform and representative than the conventional methods,and that the limit state function of UDRSM is more accurate,and the HSM is more efficient.