THE INFLUENCE OF INERTIAL EFFECTS ON THE FRACTURE OF RAPIDLY LOADED COMPACT TENSION SPECIMENS PART A - LOADING AND FRACTURE INITIATION

Compact tension specimens were loaded at 1 and 7 m/s with two differen t accelerations imposed. Experimental photoelastic patterns recorded b y a high speed camera were compared with those simulated by transient dynamic elastic Finite Element (EE.) analysis.. The positive results o f this comparison validated the EE. analysis, and gave credit to a com parison of the experimental results as well. It is demonstrated that w hen the initial acceleration of the specimen is reduced, using a dampe r in the loading device, static analysis can be applied for both testi ng speeds used. In high accelerations tests (without use of a damper), a transient dynamic stress state in the specimens is found, and there fore a dynamic analysis should be used. Furthermore, in high accelerat ion tests a transient mixed mode of loading at the crack tip occurs.