Straight tube multi-axis ratchet wheel strain testing system and method

Abstract

The invention relates to a straight tube multi-axis ratchet wheel strain testing system and a straight tube multi-axis ratchet wheel strain testing method. A hydraulic servo fatigue tester, a quasi three-point bent clamp and a strain gauge method measurement straight tube are controlled by using a sensor, data are acquired through a multi-channel dynamic strain meter, and results are output through a computer. According to the method, the testing position is flexible, and the load working conditions are diverse; and the method is novel, the design is reasonable, and the data are accurate and reliable. Meanwhile, the multi-channel dynamic strain meter has the characteristics of low drift, low noise and broad frequency response; and the fatigue tester has the functions of presetting, measuring, controlling and automatically recording the testing conditions and the testing parameters and automatically giving an alarm and halting the machine when the test is invalid or abnormal, can be widely applied to test and research of the evolution laws of multi-axis ratchet wheel strain of a pressure straight tube under various complex working conditions such as earthquake or temperature change of fluid in the tube and the like, and can be used for determining the ratchet wheel boundary of the straight tube.

Description

technical field [0001] The invention relates to a method for testing the strain evolution of a ratchet wheel at each position of a straight pipe under the action of a multi-axis cyclic load, which belongs to a straight pipe multi-axis ratchet strain testing system and method. Background technique [0002] At present, when testing the ratchet strain evolution of straight pipe materials under multi-axial cyclic loads at home and abroad, most of them are multi-axial ratchet strain tests on pipe material bar or plate standard samples, mainly by using the extensometer method and so on. However, there are many problems with this method. First, it only considers the ratchet behavior of the material itself under load, and cannot be effectively used to study the influence of the structure on the multi-axis ratchet effect. In addition, its loading conditions and types are limited, and The positioning, fixing and calibration of the extensometer are complicated, and improper operation c...

AI Technical Summary

Problems solved by technology

Although it can conduct direct loading research on straight pipe structures, this method provides a small load range and a single loading type, which is limited by itself.

In recent years, although some scholars have also proposed the strain gauge method to test the multi-axis ratchet effect of straight pipes, due to the limitations of insufficient data acquisition accuracy, limited test channels and inaccurate test position positioning, the test procedures are complicated and the results are inaccurate.

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