Modeling on the Nonlinear Rate Sensitivity of Flow Stress

유동응력의 비선형 속도 민감도에 대한 모델링

  • 호광수 (계명대학교 기계자동차공학부)
  • Published : 2004.06.01


Most metallic materials and alloys show rate independence or negative rate sensitivity in some temperature region when dynamic strain aging occurs. It is generally recognized that negative rate sensitivity is an essential feature of dynamic strain aging that can depend on strain and/or strain rate. The unified viscoplasticity theory based on overstress is applied to reproduce a change of rate sensitivity type that depends on strain or strain rate. This is accomplished through the introduction of a single new term in the growth law of the equilibrium stress, which is a tensor valued state variable of the model. It is also shown that the new term can be used to reproduce a dramatic increase of rate sensitivity in dynamic plasticity.


Constitutive Equations;Rate Sensitivity;Dynamic Strain Aging;Flow Stress;Dynamic Plasticity


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