SPHERICAL CAVITY EXPANSION IN A DRUCKER-PRAGER SOLID

A finite strain analysis is presented for the pressurized spherical ca vity embedded in a Drucker-Prager medium. Material behavior is modeled by a nonassociated deformation theory which accounts for arbitrary st rain-hardening. The governing equations of spherically symmetric respo nse are reduced to a single differential equation with the effective s tress as the independent variable. Some related topics are discussed i ncluding the elastic-perfectly plastic solid the thin-walled shell, an d the Mohr-Coulomb material. Spontaneous growth (cavitation limit) of an internally pressurized cavity is treated as a self-similar process and a few numerical examples are presented. These illustrate, for diff erent hardening characteristics, the pressure sensitivity of material response and that deviations from normality always reduce the caviatio n pressure.