考虑温度影响的基于超声回波幅度谱的钢构件应力检测

Stress measurement of steel members based on ultrasonic amplitude spectrum cosidering temperature effect

为了提高利用超声回波幅度谱检测钢构件应力的适用性,对温度影响进行研究。从温度变化导致的超声波波速变化和构件热胀冷缩两个方面考虑,提出了温度影响的修正公式。根据修正公式,开展了温度修正因子标定试验,试验结果表明,温度对应力检测的影响主要体现在对波速的影响上。在此基础上进行了考虑温度影响的钢构件单向绝对应力检测试验,对该方法的准确性和精确度进行了验证;最后探究得出高温影响下超声信号衰减的主因,即温度升高导致钢构件内部粒子热运动加剧,传播介质传递波的能力减弱。

To improve the applicability of the method for measuring the stress of steel members based on ultrasonic amplitude spectrum, the influence of temperature was investigated. Considering the change of ultrasonic wave velocity and the thermal expansion and contraction of steel members caused by temperature change, a modified formula for the effect of temperature was proposed. According to the modified formula, the calibration test of the temperature effect coefficient was carried out. From the results, the temperature effect mainly depends on the influence of temperature on the wave velocity. Based on this, the uniaxial stress measurement tests of steel members considering the temperature effect were carried out, and the reliability and accuracy of the method were verified. Furthermore, the main reason for the attenuation of ultrasonic signals under the influence of high temperature was explored. The results show that the increase of temperature intensifies the thermal motion of particles inside the steel specimen and weakens the ability of the propagation medium to transmit waves.