NUMERICAL ANALYSIS OF A SPHERICAL SHELL COMPRESSED BY A RIGID FLAT

摘要

The elastic-plastic contact between a spherical shell and a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the onset of plastic deformation is determined by finding the critical normal load and the critical interference which correspond to the onset of plastic yielding. The location of initial plastic deformation is identified as a function of material properties and spherical shell geometry. This work provides the dimensionless critical load as a function of the shell parameter X = (t/R)~*(E/Y), where t, R, E and Y are the spherical shell thickness, radius, Young's modulus and yield strength, respectively. The numerical results are compared with the solid sphere model based on Hertz's contact theory and classical shell theory in the elastic regime. The behavior of a spherical shell contacting a rigid flat plate is a strong function of the shell parameter λ.