On the plastic bulging of a circular diaphragm by hydrostatic pressure

Abstract

The hydrostatic bulging of a circular sheet clamped at the periphery is analysed on the basis of both an incremental theory and the corresponding total strain theory of plasticity. The material of the sheet is assumed to have strain-hardening capacity and to be anisotropic in the thickness direction. It is found that the incremental theory predicts that as the polar strain increases the pressure reaches a maximum and then decreases, whereas the total strain theory gives unsatisfactory results. Incremental calculations have been made for the pressure, the polar strain and the polar height at the maximum pressure (instability pressure) as functions of assumed strain-hardening characteristics and the degree of anisotropy in the thickness direction of the sheet.