  This paper develops a framework for creating damage accumulation models for
engineered wood products by invoking the classical theory of
non--dimensionalization. The result is a general class of such models. Both the
US and Canadian damage accumulation models are revisited. It is shown how the
former may be generalized within that framework while deficiencies are
discovered in the latter and overcome. Use of modern Bayesian statistical
methods for estimating the parameters in these models is proposed along with an
illustrative application of these methods to a ramp load dataset.
