中南大学学报（英文版）
中南大學學報（英文版）
중남대학학보（영문판）
Journal of Central South University
2015年
10期
3860-3867
,共8页
罗更生%谭建平%汪亮%许焰
囉更生%譚建平%汪亮%許燄
라경생%담건평%왕량%허염
low-frequencyultrasonic guided wave%bend pipe%extrados of bend%intrados of bend%FE (finite element) simulation%experimental investigation
In order to analyze the possibility of detecting defects in bend pipe using low-frequency ultrasonic guided wave, the propagation of T(0,1) mode and L(0,2) mode through straight-curved-straight pipe sections was studied. FE (finite element) models of bend pipe without defects and those with defects were introduced to analyze energy distribution, mode transition and defect detection of ultrasonic guided wave. FE simulation results were validated by experiments of four different bend pipes with circumferential defects in different positions. It is shown that most energy of T(0,1) mode or L(0,2) mode focuses on extrados of bend but little passes through intrados of bend, and T(0,1) mode or L(0,2) mode is converted to other possible non-axisymmetric modes when propagating through the bend and the defect after bend respectively. Furthermore, L(0,2) mode is more sensitive to circumferential notch than T(0,1) mode. The results of this work are beneficial for practical testing of pipes.
