AUGMENTED LAGRANGIAN FINITEELEMENTS （增广拉格朗日有限元）.pdfVIP

INTERNATIONALJOURNAL FOR NUMERICAL METHODS I N ENGINEERING, VOL. 39, 4 141-4158 (1996) AUGMENTED LAGRANGIAN FINITE-ELEMENTS FOR PLATE CONTACT PROBLEMS FERDINAND0 AURlCCHlO Dipurtimento di Ingegneria Ciijile, Uniuersita di Romu Tor Vergutu. Via dellu Ricercu Scienr$cu, 00133, Romu. I I U ~ J ELI0 SACCO Dipurtimmto di Inyegneriu Inilusrriule, Unicersita di Cussino, Via Zumusch 43, 03043. Cussino, Italy SUMMARY The present work investigates the unilateral frictionless contact between a plate and a rigid obstacle. Two sets of problems are studied: a plate constrained through unilateral edge supports and a plate seating in its undeformed configuration at a given distance from a rigid support. The attention is concentrated on two aug- mented Lagrangian formulations. The algorithmic implementation within a finite-element scheme is presented and discussed. The importance of using appropriate plate elements for the discretization of the structure is stressed. New gap elements compatible with a robust plate element are derived. Computational aspects are emphasized. A simple and effective numerical integration for the determination of the gap stiffnesses in par- tial contact with the support is proposed. Numerical results are carried out and compared with analytical solutions. The convergence to the solution of the perfectly constrained problem is numerically investigated. The inadequacy of the penalty method and t