Selivanov M. Subcritical crack growth in viscoelastic anisotropic bodies under the slow load variation

The long-term cracking of viscoelastic anisotropic bodies is under investigation. Crack growth under deformation of the body occurs by application of a slowly varying tensile load. The size of a failure zone assumed to be commensurable with a crack size. Anisotropic bodies with experimentally and theoretically determined viscoelastic characteristics are considered. In second case homogeneous anisotropic mediums with averaged characteristics model the unidirectional reinforced and layered composites. A convolution-type time operator describes the viscoelastic material properties. Use is made of the Volterra principle to determine an expression for viscoelastic characteristic. The operator function associated with the viscoelastic characteristic, using the method of operator continued fractions, is approximated by the sum of base type operators. To study the long-term fracture the theory of subcritical crack growth is used. This theory is based on the modified delta-с-model with constant size of failurezone and critical opening displacement criterion. Integral equations describe the long-term crack growth in viscoelastic medium. On the basis of the equations numerical investigations are carried out over the wide range of parameters.