Determine shape functions for a triangle with mid-side nodes from the eight-node quadrilateral by…

Determine shape functions for a triangle with mid-side
nodes from the eight-node quadrilateral by collapsing nodes 1, 4, and 8
together.

1. A sheet with a central hole is stretched by a uniform
edge stress S resulting in a stress concentration at the hole. In non-dimensional
variables: S = 100, a = 20, b = 10, r = 5, E = 1, _ = 0.3. Use ANSYS with
element Plane 182 to investigate the stress concentration (see Section 15.12).
Use 1/4 of the sheet and symmetry conditions.