Stress Concentration Around a Circular Hole in Thin Plates and Cylindrical Shells with a Radially Inhomogeneous Inclusion

Computer simulation and FEM analysis of the stress-strain state of thin plates and thin-walled cylindrical shells with a circular hole in the presence of a surrounding ring inclusion of a functionally graded material (FGM) is carried out. The influence of the dimensions of the FGM-inclusion and the law of change of its elastic modulus on the concentration of the parameters of the stress-strain state of plates and shells in the vicinity of the hole is studied. The distribution fields of stress and strain intensities of plate-shell structural elements in the zones of local stress concentration are obtained. It has been established that when using a radially inhomogeneous ring inclusion with certain mechanical properties and geometric parameters, it is possible to reduce the stress concentration factor and the corresponding strain intensities in the vicinity of the hole by more than 35%. The law of change in the modulus of elasticity of the FGM-inclusion and the width of the inclusion have a significant effect not only on the concentration of the parameters of the stress-strain state of the plate and shell but also on the nature of the stress distribution over their surfaces. The results of a series of large-scale computational experiments show that the use of an FGM annular inclusion makes it possible to reduce the intensity of both stresses and deformations around the hole, which opens up prospects for finding rational parameters of inclusions from the point of view of the maximum possible reduction in local stress concentration.