Contact friction analysis with a simple interface element Original Research Article

A simple interface element for analyzing contact friction problems is developed here. Taking nodal displacements and contact stresses as nodal unknowns, this element can simulate frictional sliding, decoupling and re-bonding of two bodies initially contacting or having gaps at a common interface. This method is based on the finite element method and load incremental scheme. The geometric and static constraint conditions on contact surfaces are treated as additional conditions and are included in stiffness equations. This simple element has the advantages of easy implementation into standard finite element programs and high accuracy for stress distribution in interface. Undesirable stress oscillations are also investigated whenever large stress gradients exist over the contact surfaces. Conventional Gauss integration scheme used to evaluate the interpolation function matrix of the interface element is found to be the source of the oscillations. Eigenmode analysis demonstrates that the stress behavior of an interface element can be improved by using the Newton–Cotes integration scheme. Finally, two examples of strip footing and pull-out problems are presented.