Experimental study on influences of inclined weak interface on the dynamic crack propagation behavior
摘要
In order to study the dynamic fracture behavior of layered materials with weak plane under impact loads combined with the split Hopkinson pressure bar, which is applied as an impact loading configuration, the dynamic fracturing process is recorded using the high speed camera, and the digital image correlation method is adopted to evaluate the strain fields around crack, failure strain and crack velocity. The results show that the running crack is more favorable to deflection after the crack encounters a weak plane under dynamic loading conditions, and the failure strain drops slightly after it deflects, while the crack velocity jumps to a high stage. Besides, the loading rate plays a significant role in crack propagation when passing through the weak interface. The crack length along the weak plane decreases with the increase of loading rate, and the running crack will expand to the matrix after it propagates to a certain distance along the weak plane. The crack velocity along the weak interface remains constant under a high loading rate, whereas both the number and the length of the crack increase after it passes through the weak plane. Moreover, the crack length along the weak plane increases with the decrease of the strength of the weak plane at a given loading rate.