Method for nondestructive detecting length of high speed highway guardrail upright post by ultrasonic guided wave

Abstract

A method of using ultrasonic guided wave to detect the length of grate column of half buried under different highway roadbed, belongs to nondestructive testing field. The method is to determine parameters of grate column before buried calculate group velocity dispersion curve of grate column before buried; select detection frequency from the curve and input the arbitrary function generator to form a single audio signal through the power amplifier module, switch modules, guided wave transceiver components, stimulate the vertical axisymmetric guided wave mode in the vertical column; the guided wave modal generate end echo when encounter the end of the column, the end echo is sent to oscilloscope through guided wave transceiver components and switch modules, determine the corresponding time of end echo, obtain the group velocity from the group velocity dispersion curve, multiple the group velocity with the echo time, divided by 2 to obtain the length of column. The present invention has the advantages of do not need to consider surrounding medium of column, high detection accuracy and of low cost.

Description

technical field [0001] The invention relates to a method for non-destructive testing of the length of an expressway guardrail column partially embedded in a roadbed by using ultrasonic guided waves, and belongs to the field of non-destructive testing. Background technique [0002] In order to prevent traffic accidents caused by cars driving on the expressway rushing out of the road or entering the opposite lane of the road, anti-collision guardrails are erected on the roadside and central isolation belt of modern expressways, and the guardrail columns are the main bearing parts of the guardrails. . Due to the harsh working environment, liquids such as moisture, humid air, and rainwater seep into the ground, causing local corrosion of the guardrail columns and resulting in corrosion and fracture of the columns. In addition, during the construction process, individual construction parties cut corners and cut corners in order to seek improper benefits, often shortening the len...

AI Technical Summary

Problems solved by technology

Due to the harsh working environment, liquids such as moisture, humid air, and rainwater seep into the ground, resulting in local corrosion of the guardrail columns and resulting in corrosion and fracture of the columns

In addition, during the construction process, in order to seek improper benefits and cut corners, some construction parties often shorten the length of the guardrail column without authorization, so that it cannot reach the designed bearing strength, causing potential accidents to the safe operation of the expressway

Since the highway guardrail column is partially buried in the roadbed, its failure mode is very concealed, and it is very difficult to effectively detect it, especially the buried part.

[0003] The current method adopted by the national standard is to pull out the column for inspection, or to excavate, and there is also a manual method of percussion and vibration. There is no relevant report on the use of ultrasonic guided wave method for detection

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