Multi-gear vibrating wire type bolt state monitoring device and using and recognizing method thereof

Abstract

The invention discloses a multi-gear vibrating wire type bolt state monitoring device and a using and recognizing method thereof. The device comprises a cable, a clamping groove, a shell, a vibratingwire, a suction block, a nut clamping ring, a bearing platform, a magnet coil, a connecting rod, a middle shaft, a base and a spring. The bolt looseness monitoring purpose is achieved based on the principle that the vibration frequency of the strings changes along with the change of the tension of the strings, and the four vibration wires are arranged and correspond to four gears with different sensitivities respectively so as to meet different monitoring requirements. After the device is connected with a to-be-monitored bolt, the initial inherent frequency of the string is measured to be omega 1; when the bolt is loosened to generate angle change, the tension of the string is changed, and the vibration frequency of the vibrating wire at the moment is measured to be omega 2; and the absolute value of the vibration frequency difference is calculated to serve as a loosening index, and the bolt connection state is evaluated. The device is calibrated by measuring the relative relation between the pre-tightening force of the bolt and the vibration frequency of the string: and a bolt early warning force threshold value is determined according to bolt design and detection standards.

Description

technical field [0001] The invention relates to the technical field of health monitoring of civil engineering structures, in particular to a multi-position vibrating wire bolt loosening monitoring device and its identification technology. Background technique [0002] With the continuous growth and development of my country's infrastructure construction, civil engineering structures tend to be large and complex, and structural health monitoring (SHM) technology is an important means to ensure the safety of engineering structures. For a health monitoring system, sensor monitoring, acquisition of structural responses, analysis and processing of measurement signals to complete structural damage detection and status assessment are the core of civil engineering structural health monitoring. As the source of damage identification and status monitoring, sensors are important for Accurate identification of state changes of engineering structures plays a key and decisive role. There...

AI Technical Summary

Problems solved by technology

Among them, the first manual method is the most common at present, but the labor cost is high, and it is greatly affected by human factors such as the personal experience of the inspectors, while the method based on the overall dynamic characteristics of the structure has a small impact on the early stage of the bolt connection loosening. Damage is insensitive, and most of the other methods require more complex theoretical support or expensive equipment, and most of them are still in the research stage, which is not convenient for a large number of practical applications

Images