北京理工大学珠海学院 2020 届本科生毕业论文超声耦合剂对压力的敏感性测试超声耦合剂对压力的敏感性测试摘 要 在超声波无损检测过程中，超声回波高度是判定缺陷当量的最重要依据。对于自动扫查装置，由于它的压紧力是固定的，所以回波高度有一致的评判准则。但是对于手工检测，由于人手臂的压力是不稳定的，因此本文希望找到一种对压力不太敏感，并且穿透性较好的耦合剂。本研究就是通过采用控制变量法进行实验来测试各种耦合剂在不同压力下的回波高度，所记录的实验数据利用 EXCEL 处理相关系数为前提，以计算出压块质量和平均回波高度∆dB 的极差值为和二次函数曲线图拟合为依据，对耦合剂的压力敏感性大小进行描述。通过结论得出压力敏感性小、且穿透性能好的耦合剂。同时，也论证了不同温度对耦合剂的黏度的影响，也可以从拟合的压力敏感性曲线对比得出施加在探头上的经验压力值。关键词：耦合剂；回波高度；压力敏感性I北京理工大学珠海学院 2020 届本科生毕业论文II北京理工大学珠海学院 2020 届本科生毕业论文Study on the pressure sensitivity of the ultrasonic coupling agent AbstractIn the process of ultrasonic nondestructive testing, ultrasonic echo height is the most important basis to determine the defect equivalent. For the automatic scanning device,because its compression force is fixed, the echo height has the same evaluation criteria. But for manual detection, because the pressure of human arm is unstable, we hope to find a coupling agent which is not sensitive to pressure and has good penetrability. This study is to test the echo height of various couplants under different pressures by using the control variable method. The recorded experimental data is based on the correlation coefficient processed by Excel, and the pressure sensitivity of couplants is described on the basis of the range value of the mass of the pressure block and the average echo height ∆ dB calculated and the quadratic function curve fitting. Through the conclusion, we can obtain a coupling ...
