A gap is a nonlinear element, used to model connection between points, edges and curves, or surfaces in your model by connecting two nodes in separated geometries.
Use gaps to represent a nonlinear flexible and friction link that can resist either compression or tension. Depending on the FEA solver, a gap can have friction or flexible characteristics. To learn how the FEA solvers treat gaps, see
ANSYS and
MSC/NASTRAN.