An experimental method and device for operating modal analysis of a cantilever beam

Abstract

The invention provides a cantilever beam operational modal analysis experiment method, which comprises the following steps that: (1) an end point of a cantilever beam is selected to be used as an excitation point to implement pulse excitation on the cantilever beam by using a steel hammer at the selected excitation point; (2) response signals generated by a reference point and a responding point after the implement pulse excitation are collected; (3) the collected signals are subjected to band-pass filtering; (4) a cross-power spectrum function between the reference point and the response point is solved, and a matrix equation formed by data of the cross-power spectrum function in different moments is built; (5) a coefficient matrix is solved by using the matrix equation, and a system pole is obtained; (6) a modal shape and a modal participation factor matrix are identified; (7) the modal assurance criterion matrix value calculation is carried out, and a modal parameter of the cantilever beam is obtained when the modal assurance criterion value is in a preset reasonable interval. The invention also provides a cantilever beam operational modal analysis experiment device. The method and the device provided by the invention have the advantages that the fast calculation can be realized; the precision is high; a better error control effect is achieved; the test intensity and the test time can be reduced; and the test efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of operation mode analysis, in particular to an operation mode analysis experiment method and device. Background technique [0002] In the teaching process of engineering testing technology, mechanical vibration and other courses, adding some modal analysis experiments can stimulate students' interest in learning, mobilize students' learning enthusiasm and initiative, cultivate students' innovative ability, and greatly improve the teaching effect. Through experiments, students can gain rich perceptual knowledge, deepen their understanding of the concept of modal parameters and their solution methods, and reduce the difficulty of students encountering problems in the process of self-study. [0003] Modal testing is often used in the extraction of modal models under actual working conditions, state monitoring and analysis, nonlinear system research, failure analysis and verification of the correctness of finit...

AI Technical Summary

Problems solved by technology

In order to improve the learning effect of students, it is necessary to carry out experimental teaching of operational modal analysis. However, there is no such experimental device at present, so the experimental method and device of operational modal analysis for teaching needs need to be studied urgently.

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