Markov Model for Wood Structural Systems

Abstract

A model to predict the ultimate capacity reliability of wood systems is developed. The model is analogous to Markov cumulative damage models. System ultimate capacity is defined as the failure of two adjacent members. The reliability of a 12‐member wood system under a snow load history is examined. Practical systems exhibit a 50‐yr ultimate capacity reliability greater than or equal to the reliability with respect to first‐member, first‐cycle failure. This reliability level is suggested as a possible future design criterion. The model is used for snow load histories that produce both stationary and nonstationary behavior over the structure life. Potentially unconservative assumptions used in the model development are explicitly stated and discussed.