I want to perform a nonlinear static analysis of the cylindrical shell of revolution subjected to internal pressure formulated using Novolzhilov shell theory and First-order shear deformation theory. I am trying to verify the above problem from paper titled 'Large deformation analysis of functionally graded shells' by Arciniega and Reddy. However, I have solved linear static and dynamic analyses of the cylindrical shell of revolution.

I have used the same formulation and code for verifying a plate-type structure for which I am getting satisfactory results. I am using the standard Newton-Raphson method for linearization.

What can be possible chances where the problem can be resolved?