Time-varying response surface method for high-temperature structural reliability analysis

The constitutive equation and carrying capacity of structure will change over time under high temperature conditions. The traditional structural reliability models are inefficient to solve these time-varying structural reliability problems. A time-varying response surface method with thermal response and response threshold value changing over time was proposed. The method can be used for high-temperature structural reliability analysis. Combined with Box-Behnken experimental design, a cross quadratic function of structure's basic variables and time was introduced for establishing a time-varying model of the thermal structural response. The function of structural response threshold value and time was established by using temperature as intermediate variable. The time-varying structural reliability calculation method was proposed when basic variables are normally distributed. A study case was given to demonstrate the applicability of this method and its greatly enhanced effectiveness besides accuracy.