Experimental and theoretical analyses of the contact-impact behavior of Babbitt ZChSnSbll-6

摘要

Contact-impact between Babbitt and steel surfaces is an ubiquitous phenomenon during the operation of oil-film bearing. To study this phenomenon, a contact-impact method of Babbitt ZChSnSb11-6 was designed and the contact-impact test was performed. For the purpose of getting a more complete understanding of the contact-impact mechanical properties of Babbitt ZChSnSb11-6, the relationships of coefficient of restitution, permanent deformation, and drop height (i.e. the initial impact velocity) were analyzed; and, the constitutive behavior between the contact force and the contact deflection was studied. Then, based on the empirical formulation developed by Brake, an indentation contact-impact model during impact events was established, which theoretically explained the contact-impact behavior of Babbitt ZChSnSb11-6. Meanwhile, the experimental results were compared with the numerical solutions solved by using MATLAB. Results revealed the established model shows a good agreement with the experimental results. The mean absolute error of coefficient of restitution was less than 0.025, and the difference for the permanent deformation after impact was less than 1%. For the contact-impact tests with different size parameters, the length and the diameter of 20 steel rods were the two significant influencing factors on the permanent deformation and coefficient of restitution of Babbitt flat surface; and, the relationship of contact force and contact deflection appeared to display the similar trend. It was concluded that the established contact-impact model has the effectiveness and applicablility on describing its contact-impact behaviors, and which can provide theoretical and experimental supports for the prediction of contact deflection and contact force of the Babbitt ZChSnSb11-6 of oil-film bearing.