Finite Difference Numerical Analysis and Experimental Measurements for Beam Profiles of Ultrasonic Creeping Wave Probe

摘要

Compare with the Rayleigh wave method, ultrasonic creeping waves critically technique for surface and subsurface defects nondestructive measurement for has the prominent advantage, which not sensitive to surface roughness in coarse-grained materials such as austenitic steel, In this paper, the propagation characteristics and beam profiles of the creeping probe were investigated using finite difference method and measured experimentally. The finite difference numerical model for reflection arc part of the IIW block was established. Through the numerical analysis, wavefront snapshots of the creeping wave propagated in the IIW block are very clear to illustrate the mechanism, and the directivity characteristic of the main beam is obtained. The creeping wave sound characteristics were observed using the dynamical photoelastic experimental method. The beam profiles of the creeping wave probe was measured on the IIW block, the experimental measurement results and the numerical analysis are in good agreement. The results are really significant to design an efficient producer for the surface and sub-surface defects detection based on the ultrasonic creeping wave method.