Probabilistic Strength Estimation for Brittle Materials under Variable Loading Rate

Abstract

This paper presents a theoretical approach for estimating the fracture strength of brittle materials under variable loads. First, a model was established on the basis of the slow crack growth concept in conjunction with two-parameter Weibull distribution for a brittle material subjected to variable loads. Assuming fracture of a brittle material under constant load, a fracture criterion obtained from the model was related with the empirical life law. Next, four-point bending test was carried out for soda glass under two step crosshead speeds. The experiment result was compared with the predictions to verify the validity of the model.