On a continuum model of an intrinsic length scale

A phenomenological model has been developed [4] which modifies the constitu tive equations of a general continuum to include the dynamic dispersive eff ects of a an intrinsic characteristic length scale. The new terms in this m odel are nondissipative and they are characterized by a single material con stant. Moreover, the modified model requires no additional initial or bound ary conditions. Here, an example problem of dynamic simple shearing of a me tal with a discontinuity in yield strength is considered to show how these new terms control strain localization. The results of the modified theory f or a rate-independent plastic material are compared with those of a viscopl astic material with no intrinsic length scale.