Modeling frictional contact in shell structures using variational inequalities

A new variational inequality-based formulation is presented for the large d eformation analysis of frictional contact in shell structures, This formula tion is based on a seven-parameter continuum shell model which accounts for the normal stress and strain through the shell thickness and accommodates double-sided shell contact. The kinematic contact conditions are expressed accurately in terms of the physical contacting surfaces of the shell. Furth ermore, Lagrange multipliers are used to ensure that the kinematic contact constraints are accurately satisfied and that the solution is free from use r-defined parameters. Large deformations and rotations are accounted for by invoking the Piola-Kirchhoff stress and the Green-Lagrange strain measures . Three examples involving a:strip friction test, ring contact and sheet co mpression tests are used to verify the developed formulations and algorithm s, and test various aspects of the solution technique. Photoelastic analysi s of the ring compression example is performed for experimental verificatio n. (C) 1999 Elsevier Science B.V. All rights reserved.