Analysis of the semi-elliptical crack in the FGM spherical pressure vessels

One of the most important analyses in the design of various structures, especially pressure vessels and their safety is the fracture mechanics. One of the important parameters in fracture mechanics is the study of the stress intensity factor of cracks in the tank wall. In the present study, the behavior of a semi-elliptical crack in a spherical pressure vessel made of functionally graded materials has been studied using Abaqus finite element software. The effects of parameters such as crack geometry, simultaneous internal and external cracks, pressure distribution, thermal load distribution, changes in the properties of the functionally graded material, and support conditions on the value of the stress intensity factor have been investigated. In order to model and analyze the stress intensity factor in this type of tank, various power, exponential and linear functions were used in the form of MATLAB code as well as a subroutine code. The results showed that with increasing pressure, the stress intensity factor increases. Crack geometry is also an important factor that has a significant effect on the stress intensity factor. So with the increase of the a/c value, the stress intensity factor also increases. Also, the examination of the support conditions shows that with the increase in the number of foundations, the stress intensity factor also increases.