DYNAMIC CRACK PROPAGATION IN BRITTLE POLYMERS

ABSTRACT Dynamic crack propagation in brittle polymers is studied in the combination of continuum mechanics analysis and microscopic consideration. The crack path is predicted by the use of energy balance method. Analytical interpretation is given for the path direction change at high propagation velocity. Related running experiments crack is executed in brittle PMMA plate in fixed sided condition. Microscopic feature of the fracture surface is examined. The mode change of the surface with the crack propagation velocity is shown from parabolic pattern region to crazing and micro-branching region. The transition from micro-branching to to macro-branching of the crack path is discussed in terms of applied loading energy.