Fracture Analysis of Thick-Walled Spherical Pressure Vessels Under Thermomechanical Loading

The present study deals with the geometry effects of the spherical pressure vessels (SPV) and the crack configuration on the variation of the stress intensity factor (SIF) through the crack line. The vessel is assumed to contain a semi-elliptical crack on the inner surface. The pressurized vessel is subjected to the pressure and thermal gradient (thermomechanical loading). The ۳-D analysis of defective thick-walled pressurized spherical vessels is conducted using the numerical finite element method (FEM). This work covers various crack configurations in vessels with different geometries. The effect of the various parameters, such as thermal gradient, Ro/Ri, a/i, and a/t, on the variation of the dominant first mode of SIF through the crack front is studied. The obtained SIFs are compared with the mechanical loading results (without the thermal gradient). The results show that crack parameters (the aspect ratio and the crack depth), the wall thickness of the vessel, and the structural loading can significantly affect the distribution of the values of SIF through the crack front. Keywords: Semi-elliptical Crack, Spherical Pressure Vessel, Stress Intensity Factor, Thermomechanical Loading

Keywords:

Stress intensity factor , semi-elliptical defect , pressurized sphere vessel , thermo-mechanical loading