Sensing optical fiber acoustic emission integrated sensing system and method for monitoring safety of structure

A sensing optical fiber acoustic emission integrated sensing system for monitoring safety of a structure, comprising:

• a sensing optical fiber temperature interference removal device and a sensing optical fiber acoustic emission demodulation device, wherein a sensing optical fiber starts from the sensing optical fiber acoustic emission demodulation device, passes through the sensing optical fiber temperature interference removal device and finally returns back to the sensing optical fiber acoustic emission demodulation device, and head and tail ends of the sensing optical fiber in the sensing optical fiber temperature interference removal device is connected to the sensing optical fiber acoustic emission demodulation device;
• the sensing optical fiber temperature interference removal device comprises a vacuum chamber module, a composite material flat slot module and a port fiber fixation module, the vacuum chamber module is connected to the composite material flat slot module, the port fiber fixation module is connected to the vacuum chamber module through a four-corner plug body, the sensing optical fiber sequentially passes through the composite material flat slot module, the vacuum chamber module and the port fiber fixation module, the vacuum chamber module, the composite material flat slot module and the port fiber fixation module are all fixed in a mounting tube, and the mounting tube is located on a temperature removal bottom platform;
• the composite material flat slot module comprises a cylinder made of a special composite material, a through hole through which the sensing optical fiber passes is provided in the center of the cylinder, a pressing cover is disposed at the top of the cylinder, and a concavo-concave glue injection groove is provided in the center of the pressing cover;
• the vacuum chamber module comprises a vacuum chamber and an outer elastic fastening ring, one end of the vacuum chamber is connected to a cover plate which is fixed in the mounting tube by glue while other end is connected to the outer elastic fastening ring, a circular hole is provided in center of the outer elastic fastening ring, an outer hard fiber protection layer is disposed in the circular hole, a conical hole is provided at bottom end of the outer elastic fastening ring, the four-corner plug body is mounted in the conical hole, a cylindrical boss extends from the four-corner plug body, the cylindrical boss is located in the outer hard fiber protection layer, the sensing optical fiber passes through the interior of the cylindrical boss, the vacuum chamber is connected to a vacuuming device outside the mounting tube, and the sensing optical fiber sequentially passes through the cover plate, the vacuum chamber and the four-corner plug body;
• the port fiber fixation module comprises a left arc-shaped pressing body and a right arc-shaped pressing body, one end of the left arc-shaped pressing body and the right arc-shaped pressing body are hinged to the bottom end of the outer elastic fastening ring while bosses extend from the other ends of the left arc-shaped pressing body and the right arc-shaped pressing body respectively, the boss is provided with a connecting device, arc-shaped surfaces of the left arc-shaped pressing body and the right arc-shaped pressing body are disposed face to face, and the left arc-shaped pressing body and the right arc-shaped pressing body form an arc-shaped pressing cavity through which the sensing optical fiber passes;
• the sensing optical fiber acoustic emission demodulation device comprises a plurality of sensing optical fiber acoustic emission sensing devices and an acoustic emission source, the sensing optical fiber acoustic emission arrangement device comprises an inner support body, a mesh module, a fiber carrying module and a bend connecting module, the inner support body, the mesh module and the fiber carrying module form a cylindrical shape, the inner support body has a four-sided concave section, the inner support body has four concave surfaces, the four concave surfaces of the inner support body are separately provided with a mesh module having a plurality of meshes, a fiber carrying module is disposed between two adjacent mesh modules, and the sensing optical fiber is contained in the fiber carrying module;
• and the acoustic emission source is connected to one end of the sensing optical fiber, other end of the sensing optical fiber is connected to a receiver, and the receiver is sequentially connected to an optical detector, a second amplifier, a signal processor, a memory, and a concrete structure monitoring and evaluation information system.