抄録
An elastic-plastic-viscoplastic rheological model is proposed to explain the longitudinal plastic waves. This model is composed of five elements and describes an instantaneous and a noninstantaneous plastic response. The calculated values according to the equation derived from this model are compared with the experimental results already reported and those from the elastic-viscoplastic rheological model which are equal to those from the Malvern type constitutive equation. The influences of an instantaneous and a non-instantaneous plastic response on the calculated values, strain - time curve, dynamic stress - strain curve and particle velocity - time curve, are discussed. The main results obtained are as follows :
(1) The calculated values from the present model agree with the experimental results better than those from the elastic-viscoplastic rheological model.
(2) With the increase of a non-instantaneous plastic response, dynamic stress becomes higher and the velocity of small strain becomes higher and that of large strain becomes lower.
(3) With the distance from the impact end, the change of dynamic stress from the proposed model becomes smaller than that from the elastic-viscoplastic rheological model.
