Spatial 20-nodes finite elements with quadratic approximation of unknown motion inside elements are used. The finite element method is used to solve the system of differential equations of motion. The law of plastic flow is chosen, a multi-linear or bilinear tensile diagram characterizing the zone of plastic flow is given, and it is assumed that components of plastic deviator deformations are directly proportional to the components of the stress deviator. The theories of small elastic-plastic deformations and plastic flows are applied. The elastic component results in to Lamé equations in displacements, unknown plastic stresses take the form of additional loads and are taken into account in the right part of the differential equations of motion. Equilibrium conditions are applied in stresses. Elastic deformations are expressed through elastic displacements with Cauchy ratios. The total deformation is presented as the sum of elastic and plastic components. The zone of plastic deformations is specified at each step of loading. It is supposed that when the equivalent loads are equal to or exceed the yield strength plastic deformations begin to develop in the elastic body. The problem of determining the shell motion is considered in the elastic-plastic formulation. The method of determining destructive loads in case of short-term force effects on a perforated cylindrical shell is proposed. It is supposed that the shell moves under the influence of short-term intense load. Stress-strain state of cylindrical shells with periodic system of openings is considered.
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