Figure 2
From: Biaxial stress controlled three-dimensional helical cracks
(a) Von Mises stress distribution in the outer spindle shell (MPa). (b–d) Scheme of the cracking model. (b) The helical cracking orbit and the forming helical angle θ with the circumference plane. As the crack tip advances, the interface delaminates at an almost identical speed. Interface delamination is continuous and synchronous with surface crack propagation. (c) Imaginary cross-section of the cracked sample with a surface crack and interface delamination. After cracking, the outer shell detaches from the inner fiber. (d) The biaxial stresses inaxial and circumferential directions around the cracking tip are mainly caused by thermal expansion mismatch.
