Estimation by second-moment approach of structural failure probabilities

Estimation of the failure probability for a system is generally difficult even if the potential failure modes are known or can be identified, because available analytical methods require determination of the sensitivity of performance functions, information on mutual correlations among potential failure modes, and determination of design points.A fundamental problem encountered in structural reliability theory is the computation of failure probability described as a multifold probability integral. The difficulty in computing this probability has led to the development of various estimation methods. Of interest here is the second ordered reliability method which is usually used to improve the accuracy of the first-order reliability method when the performance function has strong nonlinearity and the first order estimation is not sufficiently accurate.In this thesis it is taken up the subject of second moment reliability method for estimation of structural failure probabilities on different engineering problems.