超声耦合剂对压力的敏感性测试

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 agentAbstractIn the process of ultrasonic nondestructive testing,ultrasonic echo height is the mostimportant basis to determine the defect equivalent.For the automatic scanning device,becauseits compression force is fixed,the echo height has the same evaluation criteria.But for manualdetection,because the pressure of human arm is unstable,we hope to find a coupling agentwhich is not sensitive to pressure and has good penetrability.This study is to test the echoheight 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 themass of the pressure block and the average echo height A dB calculated and the quadraticfunction curve fitting.Through the conclusion,we can obtain a coupling agent with lowpressure sensitivity and good penetrability.At the same time,It can not only expound andprove the influence of different temperature on the viscosity of the coupling agent,but alsoreach the empirical pressure value applied on the probe by comparing the fitted pressuresensitivity curve.Keywords:ultrasonic coupling agent;ultrasonic echo height;pressure sensitivityn