ONE-DIMENSIONAL PROPAGATION SPEED OF AN ELASTIC-PLASTIC VISCOPLASTIC STRESS WAVE

A one-dimensional elastic-plastic-viscoplastic constitutive equation with the introduction of overstress and understress is proposed, and the propagation speed of an elastic-plastic-viscoplastic stress wave is derived using this equation. Employing the propagation theory of this wave, the strain-rate dependence of the stress, a quasi-static stress-strain curve, the high-strain-rate dependence of the stress, and the strain and strain-rate dependence of the speed can be expressed. It is also shown that the extent of the strain-rate dependence of the stress and the speed can be expressed by changing the viscoplastic coefficient eta and the modulus k2 in the elastic-plastic-viscoplastic constitutive equation and in the equation of the elastic-plastic-viscoplastic stress wave.