Study on Stress Intensity factors of Crack on Cylindrical Shell Under Axial Load and External Pressure Based on Finite Element Method

In this paper, coupled partial differential equations governing displacement field in longitudinal, circumferential and radial directions of thin/thick-walled cylindrical shell under compressive axial load and external pressure with simply support end boundary conditions based on classic shell theory have been derived. Considering the solutions in series form for displacements, these governing equations converts to three linear algebraic equations with respect to the shapes of buckling modal amplitudes. Applying a written code in MATLAB mathematical software, the critical buckling load in axial direction is calculated from the non-trivial solution of characteristic equation for buckling amplitudes. Then, with modeling crack on outer surface of cylindrical shell subjected to the buckling load and external lateral pressure in ANSYS finite element software, the crack stress intensity factors have been calculated. The effect of changes of angle of crack opening with respect to the longitudinal direction of cylindrical shell on the obtained results for crack stress intensity factors are investigated.