Interfacial debonding monitoring method for steel tube concrete tube wall based on piezoelectric impedance measurement

Abstract

The invention discloses an interfacial debonding monitoring method for a steel tube concrete tube wall based on piezoelectric impedance measurement, which comprises the following steps of: sticking piezoceramics sheets as self-driving automatic sensors on the surface of a steel tube of a steel tube concrete member; applying alternating current voltage on the piezoceramics sheets to obtain the ratio of input voltage signals with different frequencies to output current, namely the impedance of an electromechanical coupling system; transmitting an acquired electromechanical coupling impedance signal to an analytic terminal of a computer by using a GPIB (General-Purpose Interface Bus) data bus; selecting an electromechanical coupling impedance measurement result of piezoceramics at the debonding damage-free position of the steel tube concrete member as a reference value; and defining a damage index and calculating the magnitude of the damage index corresponding to each piezoceramics sheet to obtain the bonding condition of the steel tube wall at the positions where the piezoceramic sheets of the steel tube concrete member are arranged and a concrete interface. According to the interfacial debonding monitoring method disclosed by the invention, the position and the range of the interfacial debonding damage, which cannot be directly observed by naked eyes, in the steel tube concrete member can be accurately and quickly found out; and the interfacial debonding monitoring method has the advantages of high sensitivity, simpleness and convenience in operation and low price.

Description

technical field [0001] The invention relates to a monitoring method for the stripping of the steel pipe wall interface of a steel pipe concrete member, in particular to a monitoring method for the steel pipe concrete wall interface peeling based on piezoelectric impedance measurement. Background technique [0002] Concrete-filled steel tube is the main load-bearing system of the structure, and the reliable bond between the concrete and the steel tube wall is the key to ensure its mechanical properties. The peeling of the interface between the steel tube wall and the concrete can weaken the mechanical performance of the steel tube concrete member. [0003] At present, the methods for detecting the interface peeling of CFST components include manual percussion method, ultrasonic method and fiber Bragg grating monitoring method. The judgment standard of the manual percussion method depends entirely on the experience of the inspectors, which is highly subjective; the shear resis...

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Problems solved by technology

The judgment standard of the manual percussion method depends entirely on the experience of the inspectors, which is highly subjective; the shear resistance of the optical fiber is poor, and the sensor test s

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