Three-dimensional finite element analysis of self-acting foil bearings

Abstract The air bearing thickness and pressure generated when a magnetic tape moves at high speed over a recording head are governed by the coupled equation of motion of the tape and the Reynolds lubrication equation. The steady-state solution to this system of equations is obtained by direct integration using a finite element discretization. Compressibility and slip flow are incorporated into the thin film lubrication equation, and flexural rigidity is retained in the tape motion equation. The model is based on auxiliary dependent variables and uses mixed interpolation involving the four-noded Lagrangian bilinear element and the twelve-noded Adini rectangle. The semidiscrete Galerkin equations are integrated in time using a generalized Newmark method. The head/tape separations for two, fully three-dimensional, recording head geometries are analyzed using the model.