Analysis of energy conditions of brittle fracture based on the Rice-Drucker method

Abstract

The energy analysis of the thermodynamic condition for brittle fracture of solids at single loading and constant temperature based on the Rice-Drucker method is investigated for the two known models which describe the increment of defect (crack) surface area. In the first model, on the sufficiently far surface from a defect, the stress values remain the same before and after the incrementation of defect surface area. After calculations this model leads to the Griffith's criterion, in which the alteration of an entropy constituent of internal energy is equal to zero. In the second model, on the sufficiently far surface from a defect, the displacements remain the same before and after the incrementation of defect surface area. After calculations this model leads to a new criterion, in which generally, the alteration of an entropy constituent of internal energy does not equal zero. The test problem of fracture of a plate with crack at uniform tension or compression is solved.