RSURFU

This test verifies that user subroutine RSURFU properly generates a three-dimensional rigid surface. The problem consists of forming an elastic sheet around a rigid cylinder. This problem will be compared to the test shown in Finite-sliding contact between a deformable body and a meshed rigid surface, which performs the identical analysis using a Bézier surface instead of a user-defined rigid surface.

The cylinder has a radius of 5 inches, and its displacements and rotations are restrained. The sheet has dimensions of 5 inches by 10 inches and is modeled with fifty 4-node S4R shell elements. It is assumed to be elastic with Young's modulus of 3 × 10⁶ lb/in² and Poisson's ratio of 0.3. The sheet is initially positioned tangent to the surface of the cylinder, with one edge fixed to the surface of the cylinder. A pressure load of 700 lb/in² is applied to the surface of the sheet to form it around the circumference of the cylinder. All of the shell nodes are put into a contact node set with the exception of the nodes along the built-in edge. The contact node set is defined as the secondary surface, and the user-defined rigid surface is defined as the main surface. No frictional behavior is included.

This test compares two models, one using an analytical rigid surface and the other using user subroutine RSURFU. A circular plate of radius 10 and thickness 1 is modeled using two-dimensional, axisymmetric CAX4 elements. The plate is assumed to be elastic with a Young's modulus of 3 × 10⁵ and Poisson's ratio of 0.3. The displacements at the boundary of the plate are restrained. An axisymmetric rigid punch rests on one side of the plate. A load of 1.5 × 10⁵ is applied to the punch to deform the plate.

This test compares two models, one using an analytical rigid surface and the other using user subroutine RSURFU. A 10 × 10 mesh of S4R shell elements is used to model a square plate. The displacements at the boundary of the plate are restrained. A rigid punch rests on one side of the plate. A load of 3 × 10⁴ is applied to the punch to deform the plate.