Dynamic stress intensity factors for homogeneous and non-homogeneous materials using the interaction integral method

• An interaction integral is derived for 2D dynamic crack problems.
• The derived integrand does not involve any derivatives of material properties.
• There is no need to avoid the material interface using the proposed method.
• The derived technique shows good convergence and practicability.

An interaction integral is derived for the computation of dynamic stress intensity factors for both homogeneous and non-homogeneous materials. By selecting the appropriate auxiliary fields, the derived integrand does not involve any derivatives of material properties. Moreover, it can be proved that the integrand is still valid when the integral domain contains material interface. Therefore, the application of this method is more convenient. The numerical implementation of the interaction integral is combined with the extended finite element method without tip-enriched functions. Then, various homogeneous and non-homogeneous cracked bodies under dynamic loading are employed to verify the accuracy of the proposed technique.