残余应力的超声横纵波检测方法

发布时间：2018-01-05 05:03

本文关键词：残余应力的超声横纵波检测方法　出处：《声学学报》2017年02期 　论文类型：期刊论文

【摘要】：基于声弹性原理,研究板材厚度方向、螺栓轴向方向(以下简称z轴方向)宏观残余应力分布的超声无损检测方法。针对被测构件厚度不均匀对应力检测精度的影响非常大、检测原理繁杂不适合工程应用、拉伸实验中拉伸形变对应力系数测量精度的影响很大等问题,采取超声横波、纵波相结合的方法重新推导检测公式,并提出采用一发一收模式进行拉伸实验,通过对实验数据进行拟合,由公式计算出声弹性系数代替应力系数。然后结合插值、互相关等算法,采用VC++编制z轴方向残余应力超声检测软件并搭建检测系统。分别对性能为A2-70,4.8,8.8,长度依次为135 mm,100 mm,100mm的M20的螺栓进行拉伸实验,比对计算拉伸应力与检测拉伸应力,结果表明,该测量系统的绝对误差限为20 MPa,相对误差小于25%,且应力值较大时,相对误差有所减小,当应力值大于100 MPa时,相对误差小于5%,非常实用。
[Abstract]:Based on the principle of acoustic elasticity, the direction of plate thickness is studied. Ultrasonic nondestructive testing method for the distribution of macroscopic residual stress in bolt axial direction (hereinafter referred to as z axis direction). The influence of uneven thickness of tested member on the precision of stress detection is very great. The testing principle is not suitable for engineering application. Tensile deformation has a great influence on the precision of stress coefficient measurement in tensile experiment. The detection formula is rededuced by the combination of ultrasonic shear wave and longitudinal wave. It is put forward that the tensile experiment is carried out in the mode of "one send and one take-up". By fitting the experimental data, the acoustic elastic coefficient is calculated by the formula instead of the stress coefficient, and then the interpolation, cross-correlation and other algorithms are used to calculate the acousto-elastic coefficient. The ultrasonic testing software of z axis residual stress was compiled by VC and the measuring system was built. The performance of the system was A2-70 4.88.8mm and the length was 135mm / 100mm respectively. The tensile test of 100mm M20 bolt is carried out. The results show that the absolute error limit of the measuring system is 20 MPA and the relative error is less than 25%. When the stress value is larger, the relative error decreases. When the stress value is more than 100 MPa, the relative error is less than 5. It is very practical.
【作者单位】：北京理工大学机械与车辆学院检测与控制研究所;北京航科发动机控制系统科技有限公司;
【基金】：国家自然科学基金项目(51275042)资助
【分类号】：TB559
【正文快照】： 对机械构件而言,残余应力的影响是十分重要的。这种影响可能是有利的,也可能是有害的。而当其有害时,可以说是存在于机械构件中的一种无形的缺陷栜患W。眺’舰余应力的翻十分超声法检测残余应力主要依据为声弹性理论。HughePl最早提出固体声弹理论。文献3—文献6对声弹理论

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