A virtual crack extension method for thermoelastic fracture using a complex-variable finite element method

A virtual crack extension (VCE) technique using the complex-variable finite element method (ZFEM) has been developed and demonstrated for thermoelastic fracture problems. This VCE approach provides an accurate computation of the energy release rate (G) as a byproduct of the complex-variable finite element analysis and obviates the use of energy conservation integrals such as the J-integral. The crack extension is induced using imaginary coordinates and a single global estimate of G is obtained as a sum of the element contributions. Numerical examples are provided for 2D, including a bimaterial cracked plate, axisymmetric, and 3D structures. The results indicate that the complex-variable VCE approach is of the same accuracy as the J-integral formulation.