Numerical control machine tool sensitive-link identification method based on modal mass distribution matrix

Abstract

The invention discloses a numerical control machine tool sensitive-link identification method based on a modal mass distribution matrix. The modal mass distribution matrix of a numerical control machine tool is constructed with the modal mass of the numerical control machine tool and a modal shape vector, and as a result, the sensitive link of the machine tool structure can be obtained. The method is characterized by comprising the steps of (1) carrying out a modal experiment of the numerical control machine tool to obtain the modal mass of the numerical control machine tool and the modal shape vector, (2) constructing the modal mass distribution matrix of the numerical control machine tool according to the obtained modal mass and the modal shape vector, and (3) obtaining a modal mass distribution curve of all components of the machine tool by virtue of the modal mass distribution matrix, and further identifying the sensitive link of the machine tool. The method is capable of determining the sensitive link of the machine tool structure so that the weak condition of the machine tool structure is quantized, and therefore, the previously mentioned problems encountered in the process of evaluating the sensitive link of the machine tool structure by an existing method are solved.

Description

technical field [0001] The invention belongs to the field of structural modal parameter analysis of numerical control equipment, and in particular relates to a method for identifying structural sensitive links of numerical control machine tools. Background technique [0002] With the high-speed and high-precision machining, the dynamic characteristics of the machine tool structure have gradually become a bottleneck problem that restricts the efficiency of machining and the improvement of the quality of processed products. Since the dynamic characteristics of the machine tool are mainly determined by the configuration of the machine tool, it is of great significance to evaluate the configuration of the machine tool to improve the dynamic characteristics of the machine tool. The so-called evaluation of machine tool configuration is to evaluate the machine tool configuration through specific methods, find the relatively weak and sensitive links in the machine tool configuration...

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Problems solved by technology

[0004] However, the above two types of methods have certain shortcomings. The finite element method needs to establish a complete finite element model of the machine tool, which requires a large amount of calculation and takes a long time. In addition, the mesh division, the selection of the number of degrees of freedom and the constraints of the joint surface in the model There are large empirical factors in the given links; the experimental modal analysis method does not have the above defects, but this method needs to rely on the comparison of the frequency response function of each component and the results of the amplitude comparison of each component to determine the sensitive link of the machine tool. As a whole assembled from various components, the frequency response function and amplitude obtained on a single component are the result of the joint action of other components, rather than the dynamic characteristics of the component itself, and errors may occur

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