Nonlinear Bending and Collapse Analyses of a Poked Cylinder and Other Point-Loaded Cylinders

Numerical results based on the STAGSC-1 finite element computer program are presented for the geometrically nonlinear behavior of cylindrical shells subjected to inward-directed radial point loads. Three elastic shell problems are considered: the poked cylinder (single load at midlength), which is the problem of primary interest, and the venetian blind and pinched cylinder, which are check cases. Load versus displacement curves obtained for the three problems reveal that geometric nonlinear (large displacement) effects are important. For the poked cylinder it is concluded that the maximum at the limit point of the load-displacement curve corresponds to a small local snapping of the cylinder that does not result in a loss of load-carrying capacity. The paper also discusses certain features of STAGSC-1 that should be helpful to users of the program.