正交各向异性空心圆柱体中的周向超声导波

周向导波适于大直径管道纵向缺陷的超声无损检测。基于三维弹性理论,采用一种正交多项式法研究正交各向异性无限长管道中的周向导波。为验证方法的正确性与适用性,首先计算了各向同性和横观各向同性管道中的周向导波并与已有数据相比较。其次,计算了单向复合材料中不同纤维增强强度下的频散曲线,论证了纤维增强强度变化对于频散曲线的影响。最后,求解了不同径厚比下正交各向异性管道的周向导波的频散曲线,论述了径厚比的变化对频散曲线的影响。

GUIDED CIRCUMFERENTIAL WAVES IN ORTHOTROPIC HOLLOW CYLINDERS

In ultrasonic nondestructive inspection of large-diameter pipes, longitudinal cracks can be detected more efficiently by using guided circumferential waves. Based on linear three-dimensional elasticity, an orthogonal polynomial approach is used for determining the guided circumferential waves in homogeneous infinitely long orthotropic hollow cylinders. Results are compared with those published earlier to check up the accuracy and applicability of this polynomial approach. Guided circumferential wave dispersion curves for unidirectional composite pipes under different fiber intensity are calculated, and the effect of the variety of the fiber intensity on dispersion curves is shown. Finally, the guided circumferential wave dispersion curves for orthotropic pipes under different ratios of outer radius to thickness are calculated and the inherited influence of the variety of ratio on the dispersion curves is discussed.