An incremental load formulation for limit states in the reliability analysis of nonlinear systems

The present paper outlines a method for system reliability analysis of framed structures considering nonlinear structural behaviour. Limit states are formulated using an incremental load formulation in differential form considering both random strengths and stiffnesses. The first order partial derivatives thus obtained can directly be used in the First Order Reliability Methods.

A simple example study is presented to illustrate the formulation and the importance of the refinements included compared to earlier formulation. The application of the approach to more general non-linear structures is outlined.