Wilcox Paul D, Velichko Alexander, Drinkwater Bruce W, Croxford Anthony J, Todd Michael D
Department of Mechanical Engineering, Queen's Building, University of Bristol, Bristol BS8 1TR, United Kingdom.
J Acoust Soc Am. 2010 Nov;128(5):2715-25. doi: 10.1121/1.3488663.
A frequency-domain finite element (FE) method is presented for modeling the scattering of plane guided waves incident on an infinitely-long, straight feature with uniform cross-section in a planar host waveguide. The method utilizes a mesh of 2-dimensional finite elements with harmonic shape functions in the perpendicular direction. The model domain comprises a cross-section through the feature and short lengths of the adjoining host waveguide. A spatial frequency equal to the wavenumber of the desired incident mode multiplied by the sine of the desired incidence angle is prescribed for the element shape functions. An integral representation of the incident mode is used to determine a suitable system of harmonic forces to uniquely excite that mode. These are applied at nodes through the thickness of the host waveguide on one side of the feature. The displacement field is measured at nodes through the thickness of the host waveguide on either side of the feature and decomposed into reflected and transmitted modes. The cases of guided wave transmission in a featureless waveguide and the reflection of guided waves from a free-edge are examined as validation cases. Finally, the results for transmission at an adhesively-bonded stiffener are presented and compared with experimental measurements.
提出了一种频域有限元（FE）方法，用于对平面导波入射到平面主波导中具有均匀横截面的无限长直特征上的散射进行建模。该方法利用二维有限元网格，其在垂直方向上具有调和形状函数。模型域包括穿过该特征的横截面以及相邻主波导的短长度。为单元形状函数规定一个空间频率，该频率等于所需入射模式的波数乘以所需入射角的正弦。使用入射模式的积分表示来确定合适的调和力系统，以唯一地激发该模式。这些力通过特征一侧主波导厚度上的节点施加。在特征两侧主波导厚度上的节点处测量位移场，并将其分解为反射模式和透射模式。作为验证案例，研究了无特征波导中的导波传输以及自由边缘处导波的反射情况。最后，给出了在粘结加强筋处的传输结果，并与实验测量结果进行了比较。
