Modelling of crack growth by fracture damage zone

The strain energy density (SED) criterion is applied for analyzing the full range of mixed mode fracture from tensile to shear loading. A fracture damage zone (FDZ) local to the crack tip is defined and discussed in connection with the influence of crack geometry, loading and local material property. The size of FDZ tends to change continuously from statically to cyclically applied load conditions. It can be estimated from the uniaxial mechanical properties of the material. Both experimental and analytical results are examined for subcritical crack growth under static loading that depends on the type steel structures the fracture behavior of which could be represented by a single curve for the given specimen geometry.