Friction Units Durability Estimation Method Based on Friction Surfaces Limiting States Criteria System

Abstract

This article presents the fundamentals of calculation modeling of a well-known tribological triad "interaction - damage - destruction of the friction surfaces" as exemplified with the plain bearings. In order to analyze the terms of interaction between the friction surface, the algorithms of finite element method are developed for the following tasks: fluid flow in the gap; contact interaction between the surfaces taking into account nonlinear properties of the "third body".Furthermore, the article describes the durability estimation scheme, which accounts for the possibility of the simultaneous occurrence of several damaging processes: caused by the bulk fatigue and caused by the wear-contact damages of different nature. The technique is based on the spatial and temporal discretization of processes of damage accumulation (various types of damage) in the object with a non-uniform field of external actions. The levels of accumulated damage caused by fatigue and by different types of wear are evaluated in separate sections of the loaded volume. The probabilistic models of these processes of damage are used. Damage of groups of sites related by certain conditions of wear compatibility and such fatigue damage characteristics as the probability of small crack occurrence (first and any subsequent) or the probability of macro-crack occurrence (first and any subsequent) are estimated on the basis of simple formulas of probability theory. The article describes the basic principles of an approximate estimate of interference of various damage processes. Basic algorithms of general calculation methods are implemented and their working capacity is shown.