Impact shear loading of bi-material strips, a comparison of numerical and global energy analysis

Fig.1. shows a model of a test configuration which has been studied extensively [e.g. 1] to observe dynamic crack growth along a weak interface between two dissimilar materials. Here we will restrict the analysis to strips of equal height, h , but having different elastic modulii E and densities ρ . The loading is effected by impacting one arm with a projectile at a velocity which propagates the crack of length at a velocity . The stresses are predominantly uniaxial compression but the crack propagates in shear, or mode II. It has been observed that the propagation speeds are greater than a shear wave velocity of the system [1] and are sometimes referred to as intersonic. It has also been observed that very high accelerations occur during the initial phase of propagation. V a a&