Reliability Theory of Deteriorating Structures

A method of analysis of the reliability for structures with resistance deterioration is developed. Random resistance of structures is assumed to deteriorate in proportion to the deterioration factor which is a function of the intensity of applied loads. In describing the survival of deteriorating structures, the nonfailure effect is also taken into consideration. Probability distribution of the residual resistance, failure rate, and reliability function for future loads are obtained for deteriorating structures with or without experiences of past loads of known intensities. Special cases of these results coincide with the classical reliability theory for repeated loads. Numerical results are obtained for the mean residual resistance, the failure rate, and the reliability function, from which it is concluded that the deterioration effect is important in the reliability theory for repeated loads and that the form of the deterioration factor has a great influence upon the analytical results.