CONTACT ANALYSIS OF MECHANICALLY FASTENED JOINTS IN COMPOSITE LAMINATES BY LINEAR COMPLEMENTARITY-PROBLEM FORMULATION

The contact phenomena and stress distributions in the vicinity of the hole on mechanically fastened joints are investigated in composite lam inates exhibiting nonlinear elastic behavior. The effects of fastener stiffness, friction force between the fastener and the composite lamin ates, geometrical nonlinearities due to concentrated fastener load aro und the hole edge for the snug and clearance-fit in the [0 degrees]s, [+/- 45 degrees]s, [0 degrees/ +/- 45 degrees]s and [0 degrees/+/-45 d egrees/90 degrees]s laminates are also considered. An efficient numeri cal procedure is developed for the solution of the contact problems wi th Coulomb friction between the fastener and the hole based on a linea r complementarity problem (LCP) formulation in an incremental form. A nonlinear finite element code for stress analysis of laminated composi tes using Lemke's complementary pivoting algorithm is developed for so lving the LCP. The nonlinear analysis is composed of the combination o f updated Lagrangian formulation of the frictional contact problem and the nonlinear shear stress-strain relation in each ply. The accuracy, applicability and computational efficiency of the proposed method are confirmed by comparison with previous researches. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.