Wood Damage Accumulation by Stochastic Load Models

Abstract

Various creep rupture damage accumulation models are reviewed, and two recent models proposed by Barrett and Foschi are investigated in detail. Two different stochastic load models are then developed. One is for roof snow load, incorporating daily snowfall and melting, and the other is for floor live load. This latter model includes sustained and extraordinary load processes, each with their own occurrences, magnitudes and durations. Simulations are conducted for snow load models calibrated for Boston, Massachusetts, and Buffalo, New York, and for live loads for residential occupancies and office occupancies. In all cases, damage is accumulated for two different damage accumulation models, with parameters evaluated for Douglas fir. Results indicate some sensitivity to damage model, but a consistent pattern for the mean and standard deviation of damage accumulation for both damage models and all load models.