• tilting pad journal bearings

This paper deals with the description of a numerical technique developed by the author to process the data obtained from an experimental test car-riedoutto analize the non-linear behaviour of tilting pad journal bearings (TPJB). At the state of the art, this latter aspect has not been sufficiently investigated yet and deserves a full-dedicated research campaign. Thanks to the collaboration between Baker Hughes - A GE Company, AM Testing srl and Università di Pisa, it has been possible to perform some experimental test with this aim.
Starting from a brief hint to the theory that defines the rotordynamic coefficients of a lubricated journal bearing and to the difficulties to obtain them in a pure analitical or numerical way, the fundamental procedure followed to identify these coefficients in practice is described. The test bench used to execute this test is shortly presented, along with other kind of experiments that are usually done with it and the results of the last campaign commissioned on a Test Article. After a critical analysis of the literature, dedicated to the non-linear behaviour of TPJB and the respective experimental and numerical methods. A new quasi-static procedure to investigate this aspect is introduced. The main object of this job is then reported in detail: given a non-linear stiffness model based on a set of unknown coefficients, it is explained how the numerical values of these quantities are determined to obtain the best fitting for the experimental results of the quasi-static tests. Finally, the outputs of the algorithms are critically analized to look for a possible physical interpretation of these results.