A Note on the Dynamic Failure of PMMA

This paper reports our results on the investigation of dynamic failure of PMMA. Two stages have been previously identified. Kolsky (1949) applied very small strains and noted a hysteretic stress-strain behavior. Walley et al. (1989, 1994) and Rittel (2000) reported a large stress drop past a maximum and reached relatively large strains for this material. Final failure of the specimen corresponded to its shattering. In the present work we performed interrupted dynamic loading tests, so that a stage could be reached at which a well developed network of microcracks forms without further evolution to cause final failure. This intermediate stage, between lack of apparent damage and complete comminution is identified as the region of initial stress decrease, past a maximum value.