表面开口裂纹高度的超声无损测定

Ultrasonic Testing of Height of Surface Breaking Cracks

介绍了超声端点衍射法在表面开口裂纹高度中测定原理,自行设计了测量方案,实验运用斜探头折射角的正切值K=1、1.5、2、2.5的探头分别对高度为2、3、5、7、9、11、13、15、17、20mm的裂纹进行了超声测量,结果表明K=1时,具有最高的测量精确度,且随着K值的增大,测量误差呈增大趋势;对于不同高度的裂纹,运用衍射法测量的平均误差波动较小,说明衍射法具有高度选择性,对于高度越大的裂纹,测量越准确。

Testing principle of tip diffraction method in height of surface breaking crack is introduced in this paper.In the experiment the probes with K(K is the tangent value of refraction angle of the probe)=1,1.5,2,2.5 are applied to test the height of cracks which are prefabricated to 2,3,5,7,9,11,13,15,17 and 20mm high.It is shown that the best measurement precision is occurred when K=1,the measurement error increased with the increment of K value.For different height cracks,the average fluctuation of errors is small with using tip diffraction method,it shows that tip diffraction method has height sensitivity,with higher height crack,the measurement precision becomes higher.