RD-E: 0200 Snap-thru Roof

A snap-through problem is studied on a shallow cylindrical roof upon which an imposed velocity is applied at its mid-point.

The characteristic curve, caused by the limit load and achieved by simulation is compared to a reference. This example is considered a static problem.

rad-ex-fig_2-6
Figure 1.

Only one-quarter of the structure is taken into consideration and adequate boundary conditions are applied on the model sides.

The problem is solved using two different approaches:
  • An analysis by an explicit solver
  • An analysis by an implicit solver

The implicit strategy uses the arc-length method with a time step limitation. The Radioss implicit options are defined in the modeling description.

The simulations using explicit and implicit methods provide accurate results with a good evaluation of the limit load experimentally observed. A time step control with a low value is required in order to describe the nonlinear path of the load displacement curve. Both computations converge toward a single solution.