The numerical modelling of rods destruction and strain localization under impact loading

A continuum-mechanics model of fracture and damage based on phenomenological theory of dislocation and microdefects was developed [1,2] and its application to the investigation of strain localization processes under quasistatic loading was given in [3].
A dynamic problem for uniaxial stretching of rod when permanent velocities applied to its edges was solved. The structure of plastic strain localization bands was investigated. It was shown that the rod can be fractured either in the middle or in its edges depending on applied velocity range and characteristic parameters of the material. This parameters may be identified from experimental data of the specimen's quasistatic stretching tests with a constant strain rates. The applied impetus range influence upon the fracture time for different kinds of impuls was investigated. A dependence was obtained of total rod extension on the applied impuls type, which can be used as a destruction criterion for approximate models of dynamic fracture, where the microdefects propagation is not considered.