Effect of Hydrostatic Pressure on the Rate Dependence of the Fracture Toughness of High-Filled Polymeric Materials

Abstract

The paper presents results of an experimental investigation of the effect of hydrostatic pressure on the fracture toughness of high-filled polymeric materials. It has been shown that the critical value of the stress intensity factor and hence the crack propagation rate increase with increasing hydrostatic pressure of the medium. To take into account the effect of pressure on the fracture toughness characteristics of the materials under investigation, it is proposed to employ the pressure-time analogy method. The method makes it possible to represent experimental plots of fracture toughness against crack propagation rate, obtained at various levels of hydrostatic pressure, as a generalized pressure-time plot that defines the influence of loading conditions on fracture characteristics of the material. Simple empirical relations are proposed for the approximation of the experimental data obtained.