Prediction method of interface loading force in consideration of three-dimensional fractal

Abstract

The invention discloses a prediction method of interface loading force in consideration of three-dimensional fractal. When two metal surfaces are contacted with each other, the formed interface contact is the contact among micro-bulges in fact from micro perspective. The loaded micro-bulges experience three stages of deformations of elasticity, elasticity-plasticity and plasticity in succession. In consideration of the three-dimensional fractal distribution characteristic of the micro-bulges in the interface, a prediction method of metal interface loading force under dry friction is provided based on fractal geometry theory and Hertz contact theory. The method considers three-dimensional fractal surface topography, friction coefficient and elastic-plastic deformation on the contact interface on the basis of the conventional contact analysis. The method makes the interface loading force which is hard to detect easy to obtain with simple calculation and easy operation, capable of being applied to interfacial dynamic characteristics analysis of precision machinery in projects.

Description

technical field [0001] The invention belongs to the field of mechanical interface mechanics, and in particular relates to a method for predicting interface loading force considering three-dimensional fractals. Background technique [0002] In order to meet the functional requirements and assembly and transportation requirements, almost all mechanical structures in the industrial field are unlikely to be an integral structure, but formed by discontinuous parts assembly. Parts form a contact surface due to assembly, and this surface is called a contact interface. It is known from a large number of engineering practices that the surface morphology and contact behavior of mechanical parts are the most important factors affecting the performance of mechanical parts such as friction and wear, contact fatigue strength, and energy dissipation. And the dynamic performance of the whole machine system and the vibration and noise problems largely depend on the contact dynamic behavior ...

AI Technical Summary

Problems solved by technology

In the past, there were many limitations in the research on the interface loading force, mainly these problems: first, people often use the classical Hertzian contact theory directly to analyze the interface contact, and the Hertzian contact is only the elastic contact between two elastic solids, It does not consider elastic-plastic and plastic deformation, and ignores the influence of the friction factor of the contact between rough asperities. Obviously, these assumptions and limitations cannot be directly used in the analysis of high-precision mechanical interfaces (such as precision micro-nano devices, precision robot joint reducers, etc. ); Secondly, for some existing contact models based on micro-fractal theory, the establishment of them is based on two-dimensional fractal curves, and two-dimensional curves are used to replace the real three-dimensional surface topography. Unreasonable in theory and in practice

Images