A method for identifying friction-type high-strength bolts falling off in bar connection nodes

Abstract

The invention discloses a method for recognizing looseness of a friction type high-strength bolt in rod piece connection nodes, which comprises the steps of 10) arranging measuring points on a rod piece connection node splicing plate, and setting a temperature sensor and a fiber grating strain sensor at each measuring point; 20) building the linear change rate of the axial strain of the position of each measuring point along with the temperature field; 30) establishing a distribution curve of the linear change rate along the cross section of each rod piece; 40) performing integration on each of the established distribution curves to obtain corresponding integral values; 50) calculating a first-order difference absolute value of the adjacent integral values, and enabling the distribution curve along the rod axis direction to serve as a fundamental curve; 60) returning back to the step 20) to obtain a real-time curve of the first-order difference absolute value along the rod axis direction at the rth day; and 70) performing looseness recognition on the bolt by using the difference between the real-time curve and the fundamental curve. The looseness position of the high-strength boltcan be accurately recognized according to the recognition method disclosed by the invention.

Description

technical field [0001] The invention belongs to the field of health monitoring and safety performance evaluation of truss structures, and in particular relates to a method for identifying friction-type high-strength bolts falling off in connecting nodes of rods. Background technique [0002] Among high-speed railway bridges, steel truss bridges are widely used because of their advantages of large span, light weight and strong stiffness. For example, the Guangzhou-Guangzhou-Guangzhou-Guangzhou-Guangzhou Hub Cross-Dongping Waterway Extraordinary Bridge (opened to traffic in 2014), the Beijing-Shanghai high-speed railway Nanjing Dashengguan Yangtze River Bridge (opened to traffic in 2011), and the Tianxingzhou Yangtze River Bridge of the Wuhan-Guangzhou Passenger Dedicated Line (opened to traffic in 2009) . High-speed railway steel truss bridges are generally connected by friction-type high-strength bolts. This connection method transmits the shear force through the friction ...

AI Technical Summary

Problems solved by technology

[0005] Technical problem: In order to solve the problem that the friction-type high-strength bolts fall off and it is difficult to identify, the present invention proposes a method for identifying the friction-type high-strength bolts falling off in the connecting nodes of the rods, so as to identify whether the friction-type high-strength bolts in the connecting nodes of the rods fall off, and ensure that the frame bridge safety work

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