Development of the energy criterion of brittle fracture toughness for the case of combined loading

The investigation of reaction of the static-dynamical loading (pulse hit action of the striker to a notch of the previously rigidly loaded single-edge-notched specimen) of the model polymer material in wide temperature range from -90degreesC to 20degreesC was carried out. On the base of the dependence of stress and deformation tensors components distribution from the velocity of fracture propagation, the energy criterion of the fracture toughness is propose, as the modulus of the energy flow into the fracture tip. The fractographic investigations of the fracture surface of the specimens by the electron scanning microscopy methods have been made. The sizes of characteristic zones are detected, competent for the different levels of structural destruction. The critical parameters of fracture have been determinate.