Method for analyzing dynamic characteristics of bolted structure based on three-dimensional fractal theory

Abstract

The invention relates to a method for analyzing dynamic characteristics of a bolted structure based on a three-dimensional fractal theory. Modern industries rapidly develop; therefore, requirements on the machining precision of a machine tool are also increasingly high; but, the contact quality of a joint part between machine tool parts has a great influence on the machining precision of the machine tool; researches show that 60-80% of the total rigidity and 90% of the total damping of the machine tool come from the joint part; but, the integral rigidity and damping of the machine tool determine the machining precision of the machine tool; and thus, the theoretical basis can be provided for researching the integral dynamic performance of the machine tool by accurately estimating the contact rigidity and damping of the joint part. For a bolted joint surface, in combination with MATLAB numerical value simulation software and ANSYS finite element analysis software, a method for estimating the dynamic performance of the bolted joint surface is provided based on a three-dimensional fractal surface and a contact rigidity and damping model built by considering the influence of an elastoplastic deformation stage simultaneously.

Description

Technical field [0001] The invention relates to a method for analyzing dynamic characteristics of a bolted structure based on three-dimensional fractal theory, belonging to the field of structural dynamic performance research, and specifically relates to estimating the stiffness and damping characteristic parameters of the joint surface by establishing a three-dimensional fractal model, thereby achieving the prediction of the overall dynamic performance of the structure Analytical method. Background technique [0002] Bolted joint surface is a common joint surface in mechanical parts, and the contact quality of the joint surface greatly affects the overall performance of the mechanical structure. Research shows that the stiffness and damping of the joint surface affect the overall stiffness of the machine tool structure. And damping, its contact quality has become one of the important factors affecting the machining accuracy of machine tools. Therefore, the research on how to es...

AI Technical Summary

Problems solved by technology

[0003] In the 1960s, after people realized the important influence of the contact quality of the joint surface on the overall structure of the machine tool, scholars at home and abroad began to study the dynamic characteristics of the joint surface. For half a century, there have been many methods for identifying and estimating the parameters of the joint surface. People directly test the relationship between force and displacement at the joint surface to study the stiffness of the joint surface. This identification method is the most direct but is limited by the inability to consider multiple influencing parameters in each experiment.

After that, Whitehouse and Archard jointly established the W-A model. Although it is improved compared with the G-W model, it is still based on statistical analysis. This makes the statistical parameters of the surface contact analysis affected by the resolution of the instrument.

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