Finite Element Analysis of Propagation Characteristics of Ultrasonic Guided Waves in Bended Pipes
-
摘要: 通过建立弯管的ANSYS/LS-DYNA 3D模型，模拟了L(0,2)模态导波在管道中的传播形态；计算了弯管中L(0,2)和T(0,1)两种模态群速度曲线，并与相同管径和壁厚的直管做对比；研究了L(0,2)模态对管道弯头内外侧缺陷的检测能力。结果表明：导波在通过弯头时会发生模态转换，且频率越高模态转换越明显；L(0,2)和T(0,1)两种模态在弯管和直管中的频散曲线低频段时差异小而高频段时差异显著；并且，L(0,2)模态对弯头外侧缺陷检测能力要高于弯头内侧。Abstract: Using ANSYS/LS-DYNA, a 3D model of bended pipes was built and propagation of L(0,2) mode guided waves in pipes was simulated. The group velocity curves of L(0,2) and T(0,1) mode in bended pipes were calculated and compared with straight pipes of having the same diameter and thickness. Also, the ability of L(0,2) mode to detect defects located inner or outer side at bends was studied. Results showed that there would be a mode conversion when guided waves passed a bend part. When frequency increased, the mode conversion was more obvious. It was found that the difference of dispersion curves between curved pipes and straight pipes was small at low frequency and big at high frequency. And, L(0,2) mode performed better when used to detect outer side defects at bends.
-
Keywords:
- Ultrasonic guided waves testing /
- Finite element /
- Bended pipes /
- Defect
-
-
[1] 他得安，王威琪,汪源源，等.管道导波检测中激发频率的选择及灵敏度分析［J］.无损检测，2003，27(2):83-86. [2] 王悦民，沈立华，申传俊，等.管道导波无损检测频率选择与管材特征关系［J］.机械工程学报，2009，45(8)：243-248. [3] DEMMA A, CAWLEY P, LOWE M, et al. The effect of bends on the propagation of guided waves in pipes［J］.Journal of Pressure Vessel Technology, 2005, 127:328-335. [4] HAYASHI T, KAWASHIMA K, SUN Z, et al. Guided wave propagation mechanics across a pipe elbow［J］.Journal of Pressure Vessel Technology, 2005(127):322-327. [5] NISHINO H, YOSHIDA K, CHO H, et al. Propagation phenomena of wideband guided waves in a bend pipe［J］.Ultrasonics, 2006(44):1139-1143. [6] 何存富，刘增华，孙雅欣，等.基于超声导波技术对弯管中缺陷检测的实验研究［J］.中国机械工程，2005，16(18)：1662-1665. [7] ALLEYNE D, LOWE M, CAWLEY P. The reflection of guided wave from circumferential notches in pipes［J］.Journal of Applied Mechanics, 1998, 65(3):635-641.
计量
- 文章访问数: 2
- HTML全文浏览量: 0
- PDF下载量: 1
下载:
