Abstract:
The dynamic fracture characteristics of media with bedding were studied by combining digital laser dynamic caustics(DLDC) test system with distinct lattice spring model(DLSM). Three groups of specimens with different bedding angles (30°,45° and 60°) are preset. The fracture process of the specimen and the dynamic caustics spot shape change process of the crack tip are recorded with a high-speed camera. The fracture morphology of the specimen is compared and analyzed. The variation law of the stress field and the motion field of the crack tip is analyzed, and the transmission and reflection characteristics of the stress wave at the bedding are studied. Finally, the influence of the bedding parameters on the fracture characteristics of the medium is analyzed by using DLSM. The results show that the fracture characteristics of the specimen, the crack initiation time and the other parameters are different with the change of the bedding angle; the fracture of the specimen shows the tensile shear composite characteristic; the crack velocity fluctuates up and down at a certain value before reaching the bedding; the elastic modulus and thickness of the bedding will affect the dynamic fracture characteristics of the specimen.