Structure damage identification experimental method based on PVDF (polyvinylidene fluoride) piezoelectric-film sensors and strain modes

Abstract

The invention belongs to the technical field of damage identification and relates to a structure damage identification experimental method based on PVDF (polyvinylidene fluoride) piezoelectric-film sensors and strain modes. The damage identification experimental method comprises the following steps: collecting corresponding signals of all piezoelectric-film sensors after applying ambient excitation, and carrying out pre-treatment on the signals; obtaining an approximate impulse response matrix of reference points and answering points by using a natural excitation technique; constructing a generalized Hankel matrix by using the obtained impulse response matrix, and obtaining a system matrix with minimum order by using a singular value decomposition method; carrying out eigenvalue decomposition on the obtained system matrix so as to obtain structure modal parameters and modal shapes; respectively obtaining damaged or non-damaged structure modal parameters and determining damage positionsand carrying out damage identification. The method provided by the invention has the advantages that the error control is relatively good, the operability is strong, the sensitivity in damage identification can be improved, and modal analyzing and computing efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of damage recognition, and relates to a structural damage recognition experimental method based on a PVDF sensor and a strain mode. Background technique [0002] Large-scale engineering structures may be affected by shock, earthquake, corrosion, etc. during their service, causing changes in the internal structure of their materials, resulting in various damages. The continuous accumulation of damage will inevitably affect the normal work of the structure, and even lead to the destruction and failure of the structural integrity, endangering the life safety of the staff. Therefore, in the daily operation of the structure, it is necessary to carry out structural health monitoring (SHM) to detect potential damage in the structure in time, and carry out targeted repair and maintenance to ensure the normal operation of the structure, so as to maximize the Avoid major accidents. [0003] Modal analysis technology...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the disadvantages of low sensitivity, poor stability, and the need for temperature compensation sheets in the traditional strain sensor damage recognition experiment, the present invention uses a piezoelectric film strain sensor with superior performance to complete the damage experiment, and combines natural excitation technology and characteristic system realization method to broaden the Scope of application, reducing the amount of calculation during the experiment

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