Computational methods for frictionless contact with application to Space Shuttle Orbiter nose-gear tires

摘要

A computational procedure is presented for the solution of frictionless contact problems of aircraft tires. The Space Shuttle nose-gear tire is modeled using 2-D laminated anisotropic shell theory with the effects of variation in material and geometric parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. Numerical results are presented for the Space Shuttle nose-gear tire when subjected to inflation pressure and pressed against a flat plate. Comparison is made with experiments conducted at NASA-Langley. The detailed information presented assists in gaining physical insight about the structural response of the tire. The numerical studies have demonstrated the high accuracy of the mixed formulation models and the effectiveness of the computational procedure which combines both the geometrically nonlinear terms and the contact conditions in one iteration loop.