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 different accelerations imposed. Experimental photoelastic patterns recorded by a high speed camera were compared with those simulated by transient dynamic elastic Finite Element (EE.) analysis.. The positive results of this comparison validated the EE. analysis, and gave credit to a comparison of the experimental results as well. It is demonstrated that when the initial acceleration of the specimen is reduced, using a damper in the loading device, static analysis can be applied for both testing speeds used. In high accelerations tests (without use of a damper), a transient dynamic stress state in the specimens is found, and therefore a dynamic analysis should be used. Furthermore, in high acceleration tests a transient mixed mode of loading at the crack tip occurs.