A Study on Crack Propagation in Bi-materials

The growth of a crack in a bi-materials base under a building will cause the structure failure. The mechanism of this kind crack growth must be investigated. In this paper, a series of I-II mixed mode crack fracture experiments for bi-materials have been conducted. In some situations, a crack can grow from the weak medium concrete into the hard medium marble under compression load. The stress intensity factors K-I,K-II and the first principle stress sigma(1) near crack tips have been calculated. The difference in crack propagation ability between the single-material and the bi-materials specimens are also studied. The experimental results are in accordance with the sigma(theta max) fracture criterion.