Crack front rotation and segmentation in mixed mode \(\text{I} + \text{III}\) or \(\text{I}+ \text{II}+ \text{III}\). I: Calculation of stress intensity factors. II: Comparison with experiments (Q5939361)

A brittle cracked body is subjected to mixed mode I + II or I + II + III. In the considerations, three-dimensional coordinate system \(x_1\), \(x_2,x_3\) is used. The crack is located along the axis \(x_1\). The first mode load is directed along axis \(x_2\), the third mode twist is around \(x_3\), and the second mode shear is along \(x_1\). It is assused a segmentation and rotation of the crack front. The solutions of plane strain and antiplane elasticity problems are utilized. In the second part of the paper, a comparison is presented between the theory and experiments, and the energetic theory of fracture is used for a qualitative explanations of segmentation.