POSTBUCKLING ANALYSIS OF NONFRICTIONAL CONTACT PROBLEMS USING LINEAR COMPLEMENTARITY FORMULATION

A linear complementary problem formulation is proposed for post-buckli ng analysis of geometrically nonlinear structures with nonfrictional c ontact constraints. The are-length method with updated normal plane co nstraint used to trace the equilibrium paths of the structures is comb ined to generate a path-following algorithm as a predictor-corrector p rocedure. The initial load increment is determined in the predictor ph ase, considering the change of contact status. For the corrector phase , the unknown load scale parameter is eliminated using the are-length constraint. The unknown contact variables such as contact status and c ontact forces can be directly solved by the linear complementarity pro blem without any ad-hoc technique. Several newly defined buckling and post-buckling with contact constraints are solved to illustrate the al gorithm and the detail complex behaviors. It is demonstrated that the algorithm is very stable and efficient in dealing with the rather diff icult class of buckling problems with obstacles.