A NEW ADAPTIVE RESPONSE SURFACE METHOD BASED ON UNIVARIATE ANALYSIS

Response surface method has won numerous concerns in the reliability analysis of structures due to its simplicity and practicability, especially the quadratic response surface is most widely used because it contains no cross terms. However, for the complex ultimate state curved surface associated with strong nonlinearity, the accuracy of quadratic response surface is not good enough, introducing a big error in the estimation of reliability. Although, theoretically, higher order response surface method can overcome this problem, the sharp increase of the undetermined coefficient reduces calculation efficiency. Therefore, on the basis of univariate analysis of the multivariable function, an algorithm which can reasonably determine the form of higher order response surface is presented in this article, and it is able to effectively reduce the number of undetermined coefficients in response surface, so as to reduce computational difficulties; In addition, a scheme of number-theoretic selecting point applicable to response surface method has been developed. Finally, illustrative examples show that the suggested algorithm has good accuracy and efficiency.