Comparison of actual vs. simulated failure distributions of flexural wood specimens subject to 5-day load sequences

Differences exist between the various forms of damage accumulation (DA) mod els developed to represent the phenomenon of creep-rupture in wood. As a re sult, their predictive capabilities for damage accumulation also differ. Si nce these DA models were developed to describe duration-of-load effects and have been used to evaluate appropriate time-effects factors for design, th e question might arise as to which model is most accurate. A testing progra m of small, clear, southern pine specimens subject to 5-day load sequences was conducted to attempt to answer this question. The actual specimen time- to-failure distributions for prescribed load sequences were first obtained. Four commonly used DA models were then used to predict the time-to-failure distributions using numerical simulation. A comparison of the simulated fa ilure distributions with the actual failure distributions showed that the f our DA models were about equal in their ability to predict time-to-failure despite their different forms.