LOCALIZATION STUDY FOR AN ELASTIC-DAMAGE MODEL INCLUDING HIGHER-ORDERDISPLACEMENT GRADIENTS

A regularization of the local rate problem at the incipient point of l ocalization is proposed by incorporating higher order displacement gra dients in the expression of damage criterion. The condition for the on set of localization is obtained by recourse to linear instability anal ysis. It is shown that the critical damage value at localization is mo dified with respect to the model without higher order gradients. An at tempt is made to estimate the initial size of the band; it appears, ho wever, that the time constant related to the fluctuation tends to infi nity.