Nonlinear model identification of oil-lubricated tilting pad bearings

• A novel nonlinear model of tilting pad journal bearings is developed.
• The model employs Taylor series expansions of oil film forces, consistent with the transient form of Reynolds equation.
• The nonlinear model coefficients are identified using the subset selection method.
• The results are validated by comparing the model response against Reynolds equation solution.

A new method of modeling and identification of weak nonlinear behavior of tilting pad journal bearings (TPJBs) is proposed. A novel nonlinear model of a TPJB based on a Taylor series expansion of oil film forces, consistent with the transient form of Reynolds differential equation (the original model), is developed. The least mean square technique in time domain is employed to identify Taylor series coefficients of the nonlinear model. The terms with dominant effects on the nonlinear oil film forces are chosen using the subset selection method. Good agreement is achieved between the predicated response obtained from the original model and the one evaluated through using the identified nonlinear model.