Load Space Reliability Formulation for Poisson Pulse Processes

The directional-simulation procedure to estimate the zero-time failure probability and the outcrossing rate for structural systems is extended to structural frames subject to loads modeled as mixed Poisson pulse processes. The problem is formulated in the space of the load processes. The structural system resistance is represented by probabilistically defined region boundaries obtained from the presumed (known) limit state functions for the structure. The theory is applied to a simple rigid framed structural system acted on by two discrete load processes. The results obtained are compared with those derived from a consideration of bounds on the outcrossing rate for mixed sparse Poisson processes. A comparison with results published in the literature is also given. It is shown that there may be considerable differences. A detailed discussion of the reasons for these differences closes this paper.