Modeling of a cyclic shell with a local deepening on the inner surface

A mathematical model for calculating the stress-strain state (SSS) of a cyclic shell with a defect in the form of a local non-through depression on the inner surface was constructed using a three-dimensional spline version of the finite element method (FEM). An approach was proposed that combines the parameterization of the region under consideration and the cubic approximation of the target variables. The findings on the stress distribution in the defective region were presented for different locations of the depression zone. The patterns of change in the SSS of a cyclic shell with variations in the geometric parameters of the depression were established.