fe5b98b8a5-p-1840.pdf - known Zener and Holloman[1944 equation the relation between strain rate and The simplest material model which considers strain

fe5b98b8a5-p-1840.pdf - known Zener and Holloman[1944...

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26 known Zener and Holloman [1944] equation, the relation between strain rate and temperature could be expressed as K U Z p / exp (2.1) where p is the plastic strain rate, T is the absolute temperature, U is an activation energy, and K is a constant at a given stress and strain. Based on the above equation, MacGregor and Fisher [1945] developed the concept of “velocity modified temperature” - T v in the formulation of 0 / ln 1 p v A T T (2.2) where 0 is the reference plastic strain rate, and A is a constant related to the activation process for plastic flow. This equation shows that the flow stress, under the temperature T and strain rate p , is equivalent to the stress under temperature T v and reference strain rate 0 . Many other relations, such as the Johnson-Cook model, have been developed since then. Stevenson and Oxley [1970 and 1971] carried out turning and compression tests on a 0.13%C steel, and showed the „„velocity modified temperature‟‟ model fits experiment data with valid material reasons. This concept became one of the key
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  • Fall '16
  • Karyl Sabbath
  • strain rate

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