中文摘要：

分析了超声散斑数字干涉法测量应变的原理,建立了水下测量系统,对涂敷了铝粉的不同粗糙度的试件表面进行了实验测量,测量误差在6%以内.误差分析表明：试件中部测点的误差比两侧测点的误差小;试件表面粗糙度越大测量误差越小;试件表面应变越大测量误差越小.通过对误差作进一步实验分析,发现步进电机的误差较大,解决的方法是增加散斑颗粒的横向尺寸.针对信号不稳定,采用重复测量并在计算时取平均值的方法来消除误差.

英文摘要：

The ultrasonic speckle digital interferometry method has been applied to measure the surface strain,and the underwater measurement system been established,with which the surface strain of the different roughness of specimen coated aluminum powder was measured.Measurement error is within 6%,and the analyses of experiment errors shows that the error of the measuring point in the middle of specimen is smaller than the error of the measuring point on both sides.The greater the specimen surface roughness,the smaller the error of measurement.For larger strain surface,the error was smaller.After further experimental analysis on error,it was found that stepper motor has great error,the solution is to increase transverse size of speckle.The voltage instability caused that transmitting and receiving signal was not stable,the repeating measurement and average calculation method is used to eliminate the error.