An improvement of the response surface method based on reference points for structural reliability analysis

The Response Surface Method (RSM) is a powerful technique to evaluate the structural reliability. However, for a Limit State Function (LSF) with highly non-linear, the accuracy of the approximation of the failure probability does not depend very much upon the design point. It is necessary for RSMs to consider the design point and the non-linear trend of actual LSF around the design point, because both of them influence the failure probability. Thus, in order to improve the fitting precision of the Response Surface Function (RSF) to the actual LSF over a larger region containing the design point, the reference points of experimental points are constructed in this paper. Experimental points used to obtain parameters of a RSF are selected according to the information of reference points. Four examples are discussed in detail. The numerical results indicate that the accuracy and the efficiency of the proposed method are both desirable for both numerical and implicit LSFs, and the proposed method is superior to the classical RSM in terms of efficiency and accuracy.