Bogdan D. Numerical analysis of crack growth resistance in spatial prismatic bodies with elastoplastic deformation based on the modified method of reactions

The thesis covers the analysis and development of effective approaches for J-integral determination in the discrete FEM models under linear and nonlinear deformation of the bodies and the development algorithms for its calculation considering the finite element discretization of SFEM. A modified version of the method of reactions was developed based on the use of the nodal displacements and reactions close to the crack tip and in this case the path of integration is absent. A study of convergence and invariance of the J-integral calculation results by modified method of reactions were made in the case of elastoplastic deformation and mixed fracture in three-dimensional problems. The new solutions for the crack growth resistance determination of crucial objects with the presence of semi-elliptical cracks of various sizes were obtained.