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 ε ̇ smooth = u / tl . For notched specimens, however, the strain rate at the notch root ε ̇ notch should be analyzed accurately. In this study, therefore, the strain rate concentration factor defined as K t ε ̇ = ε ̇ notch / ε ̇ smooth is studied with varying the notch geometry and specimen length. It is found that the strain concentration factor K t ε ̇ can be estimated from stress concentration factor K t ∗ . [ABSTRACT FROM AUTHOR]