Buckling, Postbuckling, and the Flow Through a Tethered Elastic Cylinder Under External Pressure

A thin-walled elastic cylinder is tethered by numerous springs to an outer rigid cylinder. As external pressure is increased, the elastic cylinder will remain circular until a critical pressure difference is attained. The nonlinear governing equations for large deflections are formulated. The stability analysis shows the elastic cylinder may buckle with more than two circumferential waves due to the stiffness of the springs. Postbuckling shapes are integrated numerically by a quasi-Newton method. The flow through such a partially collapsed shape is then computed by a finite element method.