An Analysis of Dynamic Fracture in an Impact Test Specimen

Numerical simulations of fast fracture in four cases of dynamic tear test experiments on 4340 steel are performed using a moving singular finite element method. The experimentally measured crack propagation histories are used as input data to the so-called generation phase simulations to determine the dynamic stress intensity factor histories. In most numerical analyses of dynamic fracture specimens, the load and support points have been treated as fixed boundary conditions. In the present paper, more realistic boundary conditions (contact/no-contact), in which the specimen can separate from the tup and the supports are introduced. The results are also discussed in the light of current controversies surrounding the dynamic fracture toughness properties governing crack propagation under impact loading.