Response and Failure of Internally Pressurized Elliptical Composite Cylinders

Abstract

The responses of a quasi-isotropic elliptical cylinder evaluated using a geometrically linear analysis are compared to the responses evaluated using a geometrically nonlinear analysis. It is shown that geometric nonlinearities tend to flatten certain responses in the crown region and reduce the magnitude of certain responses in the boundary region. An evaluation of failure using the Hashin and maximum stress failure criteria and geometrically linear and nonlinear analyses is presented. The failure criteria are used to assess the mode of failure, the location of failure, and the pressure at failure. Both criteria predict first failure to occur at the clamped boundaries because of matrix cracking due to stresses in the plane of the cylinder wall. The predicted failure pressures and circumferential locations are very similar for the two criteria, and the nonlinear analyses predict slightly higher pressures at somewhat different circumferential locations.