PROBABILITY OF PLASTIC COLLAPSE OF A STRUCTURAL SYSTEM UNDER NONSTATIONARY LOAD PROCESSES

This paper deals with the reliability analysis of a complex structural system, in which the failure of the system is due to plastic collapse . Of particular interest herein is the computation of the time-variant probability of the structural system failure under nonstationary load processes. The theoretically most attractive approach for this type o f problem in time-dependent structural reliability analysis is to empl oy the concept of first passage probability in stochastic process theo ry. Because the use of the generalized Rice formula poses some difficu lty, the outcrossing problem will be formulated herein in another way, i.e., using the original Rice formula directly. This situation allows the multidimensional integral to be reduced to a one-dimensional inte gral. Also it can include smooth nonstationary processes as well as ti me-variant domain boundaries. An example is given to illustrate the me thod.