Relationship between strain rate concentration factor and stress concentration factor

In this study, the strain rate concentration is considered for high speed tensile test, which is now being recognized as a standard testing method. To evaluate the impact strength of engineering materials under high impact speed, Izod and Charpy tests are unsuitable since they cannot control the impact speeds and therefore do not coincide with the real failure of real products. For smooth specimens, the strain rate can be determined from the tensile speed u/t and specimen length l as ̇smooth =u/tl. For notched specimens, however, the strain rate at the notch root enotch should be analyzed accurately. In this study, therefore, the strain rate concentration factor defined as Kte=enotch/esmooth is studied with varying the notch geometry and specimen length. It is found that the strain concentration factor Kte can be estimated from stress concentration factor Kt