基于超声法的螺栓轴向应力温度影响研究

Research on the effect of temperature on bolt axial stress based on ultrasonic method

温度周期性变化引起的热胀冷缩是造成螺栓松动的可能,而螺栓紧固扭矩的直接体现为螺栓轴向应力。本文通过研究温度影响下基于单波法的螺栓轴向应力检测技术,以M16×60、A2-70螺栓作为研究对象在进行精度验证后,发现当其紧固件在经历-40~40℃的温度循环时,随着温度增加其轴向应力大致呈上升趋势且最大变化量大致在22.71~32.28 MPa内,同时恢复初始温度后紧固件发生了一定的松动,且夹紧长度越大松动程度越大。

The phenomenon of thermal expansion and cold contraction caused by periodic temperature changes might further cause the problem of bolt loosening,and the bolt tightening torque is directly reflected in the axial stress.This paper studies the bolt axial stress detection technology based on the single-wave method under the influence of temperature.After accuracy verification with M16×60 and A2-70 bolts as the research object,it is found that when the fasteners underwent the temperature cycle of_40~40℃,with the increase of temperature,the axial stress generally increases and the maximum variation is approximately 22.71~32.28Mpa.At the same time,the fasteners loosen to a certain extent after the initial temperature is restored,and the greater the clamping length is,the greater the degree of looseness is.