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

A one-dimensional elastic-plastic-viscoplastic constitutive equation w ith the introduction of overstress and understress is proposed, and th e 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 s train 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 coefficie nt eta and the modulus k2 in the elastic-plastic-viscoplastic constitu tive equation and in the equation of the elastic-plastic-viscoplastic stress wave.