In papers [11, 15 18] the solution relations and the algorithm of the method of block iterations of solving linear and nonlinear equations by the semivanalytic finite element method for curvilinear inhomogeneous prismatic bodies are realized. In paper [1], a numerical study of the convergence of solutions was performed, and a wide range of test problems for bodies with smoothly and abruptly changing physical and geometric characteristics in elastic and resilient-plastic formulation was considered. In paper [21], to confirm the reliability of the results obtained on the basis of the semi-analytical finite element method, the effectiveness of this approach for the calculation of curvilinear inhomogeneous prismatic objects is shown. Solving control problems of the theory of elasticity, thermoelasticity and thermoplasticity, as well as problems of shape change makes it possible to draw conclusions about the reliability of the results of the study of a selected class of objects based on the developed methodology and implements its application package.
 In this work, using the method described in the above works, a numerical analysis of the stress-strain state of a spatial object was performed, namely the study of the influence of flange thickness on the nature of the development of plasticity zones in the casing detail. It should be noted that the use of a thickened flange allowed to localize the zone of plasticity and its length in this case does not exceed half the length of the bell. In this case, the additional cost of material for the manufacture of thickened flange is fully justified. This reduces the level of plastic deformations and stresses in the hazardous area and prolongs the life of the casing detail.