Curved thermal crack growth in nonhomogeneous materials with different shaped external boundaries II. Experimental results

Curved thermal cracks are considered running along special principal stress trajectories in self-stressed two-phase solids with different cross sections. The resulting mixed boundary-value problems of the stationary plane thermoelasticity are solved by applying the finite element method. Moreover, using appropriate directional criteria established for crack path prediction, the further extension of thermal cracks starting at the external surfaces of different shaped two-phase solids has been determined. Furthermore, the corresponding fracture mechanical data like crack edge displacements, strain energy release rates and stress intensity factors, respectively, have been calculated. Finally, the theoretical investigations given in part I of the paper are compared with experiments using differing optical methods of the experimental stress analysis. The experimental results reported in part II of the paper and the theoretical calculations show a reasonable agreement.