Calculation of equilibrium position and dynamic coefficients of a journal bearing using free boundary theory

A finite element method which is based on the variational inequality approa ch, is introduced to calculate the oil film pressure distribution of a jour nal bearing. The cavitation zone is found by solving a linear complementary problem. By means of this approach a perturbation can be performed directl y on the finite element equation and, consequently, the Jacobian matrices o f the oil film forces are obtained concisely. The equilibrium position of t he bearing at a given static load is found by the Newton-Raphson method and as byproducts, dynamic coefficients are obtained simultaneously without an y extra computing time. Numerical examples show that the method works satis factorily. [S0742-4787(00)02302-X].