Method for identifying rigidity weak link of elastic support beam by utilizing curvature angle index

Abstract

The invention discloses a method for identifying a rigidity weak link of an elastic supporting beam by utilizing a curvature angle index, belongs to the field of mechanical vibration, and solves a keyproblem of identifying the rigidity weak link of a combined machine tool structure. A machine tool structure which can be equivalent to an elastic supporting beam structure is adopted. The method comprises the steps of taking the finite element model of the elastic support beam structure as a numerical example, acquiring dynamic response data of each node of the numerical model by utilizing a state space method, establishing a relationship between data fitted by a least square method and actually measured data, and identifying a rigidity weak link by adopting a curvature angle new index. Modal parameters under all orders of modals are obtained through a hammering method, relative data such as displacement are obtained through a modal state space method, and inaccuracy caused by a displacement relative measurement method and interference of noise on the data obtaining process in the experiment test are eliminated through system reconstruction. According to the method, the problem of inaccurate joint surface modeling in finite element analysis is solved, and the problems of algorithm convergence and blindness in an Update method can also be solved.

Description

technical field [0001] The invention provides a new method based on the vibration test data and uses the new index of curvature rotation angle to identify the weak link of the structural rigidity of the elastic support beam, which belongs to the field of mechanical vibration test. Background technique [0002] The excellent processing performance of the machine tool is closely related to its dynamic performance. The deformation and vibration of the machine tool will not only affect the accuracy of the machine tool and the surface quality of the workpiece, but also reduce the production efficiency and tool durability, and even reduce the machine tool. service life. Stiffness is an important parameter that affects the precision of CNC machine tools. Improving the stiffness of machine tools can effectively improve the machining accuracy of parts. In order to improve the stiffness of the machine tool, it is necessary to understand the stiffness of each link of the machine tool,...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that in the model parameter correction, the joint surface parameters between the machine tool structures are the main target of correction, followed by the geometric shape of the machine tool structure

However, there are too many positions of the joint surface correction parameters, and there are many correction parameter methods to make the analysis results of the finite element mode consistent with the experimental modal analysis results, so the correction method is complicated and blind, which leads to the reliability of the final analysis results The reliability is not high, and the entire analysis process cycle is too long

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