Description of the Lubricant Behavior Based on the Theory of Elasto-Viscoplastic

The aim of the work is to provide a mathematical description of the lubricant’s behavior model used in sliding bearings of bridge structures. It was previously established that the Maxwell model does not correctly describe the lubricant’s behavior in a wide range of temperatures and deformation rates. The lubricant model should take into account not only viscosity but also plasticity. The Anand model, which was adapted by introducing temperature dependencies for a number of material parameters, was chosen to describe the lubricant behavior. The functionality of the previously created procedure for identifying material properties was also expanded on the modified Anand model. This made it possible to obtain a lubricant mathematical model with an error of less than 5% in the operating temperature range from −40 to +80 °C. The study included a description of the behavior model for two lubricants: CIATIM-221 and CIATIM-221F. CIATIM-221F differs from CIATIM-221 by including superfine particles of polytetrafluoroethylene (PTFE) to improve properties. The study confirmed that the modified Anand model allows describing the material behavior more accurately than the Maxwell model. It was found that the samples behave as a solid over the entire temperature range (from −40 to +80 °C). A comparative analysis of the thermal behavior of CIATIM-221 and CIATIM-221F was performed.