A normal interface rigidity prediction method considering three-dimensional fractal

Abstract

The invention relates to a normal interface rigidity prediction method considering three-dimensional fractal, the method comprising the steps of: improving a curvilinear function describing two-dimensional fractal into a correction function simulating three-dimensional fractal topography and expressing amplitudes of peaks and troughs described by the function as contact deformation quantities; making contact between two rough micro-bulges equivalent to contact between a rigid plane and an equivalent micro-bulge, wherein the actual contact area between the equivalent micro-bulge and the rigid plane meets a=pi R delta; separately calculating the deformation quantities of an elastic deformation stage and an elastoplastic deformation stage; calculating an area distribution function and the actual contact area; calculating the rigidity of a single micro-bulge and total interface rigidity; calculating the rigidity kn1 of the elastic stage, the rigidity kn2 of the elastoplastic stage and the total interface rigidity. The prediction method for acquiring the between-interface rigidity of precision machinery is simple and easy to implement. The method takes into consideration elastoplastic deformation of micro-bulges, contact friction factors and three-dimensional fractal distribution and obtained results can provide technical reference for prediction and control of dynamic characteristics of interfaces.

Description

technical field [0001] The invention relates to a technique of mechanical interface mechanics, in particular to a method for predicting the stiffness of a normal interface considering three-dimensional fractals. Background technique [0002] The surface of the part processed by the machine tool is smooth from the macroscopic point of view, but it shows a large number of rough bodies from the microscopic point of view, that is, the part has a rough surface morphology. Rough surface topography has an important influence on the friction, fatigue and vibration noise on the interface. Through the observation of metal surface topography, scholars have found that the surface topography at different measurement scales has statistical self-affine and self-similar characteristics, so the fractal theory is introduced and widely used in the description and contact of rough surface topography. analyze. Accurate modeling of the characteristic parameters (mainly contact stiffness and con...

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Problems solved by technology

[0005] Aiming at the inefficiency and poor accuracy of obtaining the mechanical interface stiffness in the prior art, the problem to be solved by the present invention is to provide a method that considers three-dimensional fractals that makes it easy to obtain the interface stiffness that is difficult to detect and improves the accuracy of prediction. Interface Stiffness Prediction Method

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