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Holes have an important influence on dynamic fracture process of brittle materials. In this paper, the influence of the hole offset distance (HOD) on the movement process of the explosive crack is studied. Polymethyl methacrylate (PMMA) is used as the experimental material, and different HOD holes are drilled on the PMMA plate. A new digital laser dynamic caustics system is employed to observe the crack tip dynamic stress intensity factor and crack growth velocity of PMMA plates with different HODs under explosive loading. The results indicate that holes reduce the peak velocity of explosive crack propagation. Moreover, the interaction between the stress wave reflected by the hole and the explosion stress wave is the main cause of crack deflection. Lastly, as the HOD increases, the crack motion trajectory is weakened by the interference of the holes, which gradually decreases corresponding stress intensity factors. With the increase of HOD/d, the crack arrest effect of empty hole decreases gradually.

Using polymethyl methacrylate (PMMA) as the test material, three-point bending tests were carried out on single hole and double hole specimens with prefabricated cracks at the bottom. The fracture ...

In this paper, the crack propagation behavior of a polymethyl methacrylate plate with double holes under explosive load is investigated. The propagation process of the explosion crack is recorded using a new digital laser dynamic caustics system, in which a high-speed camera and the explosion loading are employed. Firstly, the interaction process between the explosion stress wave and the empty hole reflected stress wave is analyzed using caustics. Moreover, the deflection law of the explosion crack is discussed. Secondly, the relationship between the propagation distance, velocity, stress intensity factor of the explosion crack tip, and the distance between the two holes is analyzed. Finally, the explosion process is analyzed using numerical simulations. It is concluded that the evolution law of the explosion stress wave in during the simulation process is similar to the caustics diagram. Lastly, the time-varying law of the stress between the double holes is obtained.