Fiber acoustic emission sensing apparatus and method for service behavior of hydraulic concrete structure

A method of a fiber acoustic emission sensing apparatus for a service behavior of a hydraulic concrete structure, comprising the following steps of:

• first step:
• establishing each component in a sensing fiber acoustic emission laying module, equipping a sensing fiber with a certain length, rotating a first side plate and a second side plate to form a 60-degree included angle with a horizontal plane, so as to form a main common cavity;
• second step:
• rotating a first arc-shaped cover and a second arc-shaped cover to drive a first arc-shaped pressing body and a second arc-shaped pressing body to move, respectively pressing a first sensing fiber and a second sensing fiber in the arc-shaped fiber-carrying channel through a bulge between the first arc-shaped pressing body and the second arc-shaped pressing body, and laying four sensing fiber acoustic emission laying devices in a concrete structure to be tested by external grooves;
• third step:
• opening and debugging each sensing fiber acoustic emission laying device, adjusting and marking the first sensing fiber and the second sensing fiber in the four sensing fiber acoustic emission laying devices laid in the concrete structure, and modulating femtosecond pulses of the first sensing fiber and the second sensing fiber through a laser optical source;
• fourth step:
• femtosecond pulse optical information of the first sensing fiber and the second sensing fiber in the four sensing fiber acoustic emission laying devices being affected by acoustic emission waves in an acoustic emission source when the concrete structure generates the acoustic emission source under the effect of an external load, and the acoustic emission waves resonating with a common cavity circular hole, a common cavity hexagonal hole and a main common cavity in different time and frequencies, the femtosecond pulse optical information being secondarily amplified and delayed in physical size, and secondarily amplified and delayed femtosecond pulse optical information being transferred to the first sensing fiber and the second sensing fiber;
• fifth step:
• receiving and detecting varying femtosecond pulse optical information through the receiver and the optical detector, and then conducting de-noising processing and data storage on the varying femtosecond pulse optical information through the signal processor and the memory, so as to collect the varying femtosecond pulse optical information in an information system for concrete structure monitoring and evaluation;
• and
• sixth step:
• drawing a varying time-history curve of the varying femtosecond pulse optical information in the information system for concrete structure monitoring and evaluation to reflect a change of the acoustic emission waves generated by the acoustic emission source, so as to dynamically monitor and detect the concrete structure.