Miniature piezoelectric impedance device and method for online health monitoring

Abstract

The invention provides a miniature piezoelectric impedance device for online health monitoring. A piezoelectric ceramic wafer sensor is stuck on a to-be-measured structure, an impedance converter generates an excitation signal, the excitation signal is applied to the to-be-measured structure through the piezoelectric ceramic wafer sensor, and a feedback signal is collected and sent to a system control module; when the defect of the to-be-measured structure drives the piezoelectric ceramic wafer sensor to deform, a sampling signal returned by the piezoelectric ceramic wafer sensor changes, andthe system control module judges the health status of the to-be-measured structure according to a set threshold value. The device and the method in the invention have the characteristics of simple structure, light weight, small volume, low price, no pollution, easy operation, good stability, strong environmental tolerance, wide use structure range and the like, and online and continuous monitoringcan be realized.

Description

technical field [0001] The invention relates to an online health monitoring device and method, which are used for real-time online detection of state changes and damage development of various parts of structures or components. Background technique [0002] Aeronautics and navigation structures may be slightly damaged during production, processing, long-term storage, and loading, unloading, and transportation in simulation exercises; large buildings or facilities are prone to accumulate various initial defects under the influence of wind, temperature, humidity and other environmental factors for a long time , these defects and damages will continue to expand into tiny damages after a gradual evolution over time; precision instruments, complex structural parts, etc. are prone to fatigue damage or damage expansion under the action of continuous load. These damages often lead to accidents if they are not repaired in time, so real-time monitoring of the structural state is requir...

AI Technical Summary

Problems solved by technology

At home and abroad, there are some equipment for non-destructive testing based on impedance analysis method for specific objects, but there are various problems, or they are easily affected by the weak vibration and temperature of the environment, resulting in unstable electrical impedance measurement results, or using a wide range and The price is expensive due to multi-functional integrated components, or it is difficult to implement and popularize because of the factors of large volume and weight, complicated actual operation and result analysis, or it is assembled with a simple combination of existing instruments, resulting in complicated actual operation, or Because the sensor part is damaged by the corrosion of the environment, it cannot be monitored sensitively for a long time

For example, the Agilent 4924A instrument of Agilent Technology Company in the United States has a larger volume of 0.04m 3 , weighs more than 20kg, and costs nearly 300,000 yuan. The quality and volume of the power interface and data input and output modules are relatively large, which seriously affects the use of long-term health monitoring of the structure in practice; my country's 2016 invention patent "a piezo-resistance-based The bridge cable corrosion monitoring system and method based on the current method” has a relatively narrow application area and still faces the problem of long-term monitoring; at the same time, the utility model patent in 2016 “a piezoelectric impedance measurement device for structural health monitoring” used Arbitrary waveform generators and digital oscilloscopes have not been optimized for module design, and their cost is still more than 50,000 yuan. At the same time, they are bulky, making it difficult to realize long-term online monitoring of outdoor structures

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