Challenges in the reliability analysis of large dynamic systems - A novel approach

There is a vacuum in the reliability analysis procedures for large structural systems. The risk analysis procedures should explicitly satisfy all major sources of nonlinearity expected just before failure and the associated uncertainties. One can argue that simulation-based formulations can always be used in the absence of any such procedure. The authors observed that one deterministic nonlinear finite element-based realistic analysis of large systems may take over 5 hours of continuous running of a computer. For the risk analysis of the order of 10-3, at least 10,000 simulations will be required. Thus, it may take years of continuous running of a computer, and yet the extracted probability of failure information may not be representative. The research team is now in the process of developing and verifying a hybrid approach consisting of nonlinear stochastic finite element method, the first/second-order reliability method, response surface method, and advanced factorial schemes. This hybrid approach will be presented in the paper.