Reliability analysis to resolve difficulty in choosing from alternative deflection models of RC beams

The probability of failure in reliability analysis depends on the integration of the joint probability density function (PDF) of uncertain variables at the violation regions of limit state functions corresponding to these variables. There might exist uncertainty in choosing computational models of resultants, which includes uncertain variables, and are incorporated in the limit state function. This uncertainty is not random, but can be considered as an epistemic uncertainty, since this uncertainty represents ambiguity in choosing from among alternative computational models; such an uncertainty is known as “non-specificity”.