Systems Reliability With Multiple Design Points Through Evolutionary Strategies
In structural reliability analysis there could be several limit state functions with multiple design points. The missing of one or more of these design points can be responsible for significant errors on the system reliability evaluation. In this paper, a simple version of the Evolutionary Strategies (ES) algorithm is combined with the First Order Second Moment method (FORM) to perform the reliability analysis of systems with multiple design points. The ES algorithm is used to perform a preliminary identification of the design points (local maxima). These design points approximations are used as initial guesses in the HL-RF (Hasofer and Lind–Rackwitz and Fiessler) method in order to calculate the true design points. The system failure probability is then evaluated with FORM approximation for series systems. The proposed methodology is applied to the analysis of three non-linear limit state functions with Normal and non-Normal random variables and the results are compared with those obtained with the Monte Carlo method.