Method for recognizing looseness of friction type high-strength bolt in rod piece 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 fields of health monitoring and safety performance evaluation of truss structures, and in particular relates to a method for identifying the falling off of friction-type high-strength bolts in connecting nodes of rods. Background technique [0002] In high-speed railway bridges, bridge structures such as steel truss bridges are widely used due to their advantages of large span, light weight and strong rigidity. For example, the Guangzhou Junction of the Guiguang-South-Guangzhou Railway spans the Dongping Waterway Super Bridge (opened to traffic in 2014), the Nanjing Dashengguan Yangtze River Bridge on the Beijing-Shanghai High-speed Railway (opened to traffic in 2011), and the Tianxingzhou Yangtze River Bridge on the Wuhan-Guangzhou Passenger Dedicated Line (opened to traffic in 2009) . The members of high-speed railway steel truss bridges are generally connected by friction-type high-strength bolts. This connection metho...

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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