About the accuracy of a novel response surface method for the analysis of finite element modeled uncertain structures

A study about the accuracy of a recently proposed method for the evaluation of the response of uncertain FE discretized structures is presented. The method can be considered a response surface technique employing ad hoc ratios of polynomials as performance functions, which have the favorable property to furnish the exact response for statically determinate structures. It is shown that when statically indeterminate structures are considered the results are still very accurate, in spite of the number of redundancies, especially if the performance functions include the cross terms. Namely, the explicit relationship between the derived and basic random variables obtained by the method is very close to the actual one. The method is very efficient from a computational point of view as a small number of sampling points are chosen and the evaluation of cross terms does not require extra analyses. The numerical examples evidence that the approach is always more accurate than the response surface method based on second order polynomial performance function. (C) 2003 Elsevier Ltd. All rights reserved.