Deschamps M, Hosten B
Laboratoire de Mécanique Physique, Université de Bordeaux I, URA C.N.R.S. No. 867, Talence, France.
J Acoust Soc Am. 1992 Apr;91(4 Pt 1):2007-15. doi: 10.1121/1.403685.
In this paper both theoretical and experimental investigations on the reflection and transmission of an incident plane wave by immersed viscoelastic orthotropic plates are presented. Taking the anisotropy of the layer into account the reflection and transmission coefficients are expressed in terms of nine complex elastic constants. In agreement with the Snell's laws, any waves generated in the layer are bulk heterogeneous plane waves. Using a method already described in the isotropic case, the reflection and transmission coefficients are obtained as a function of the reflection and refraction coefficients of bulk heterogeneous plane waves at the two single solid/liquid interfaces, which limit the plate. In this way, these coefficients can be easily expanded in Debye's series. In addition, for many incident and azimuthal angles, the calculations are compared with trial results on a composite made of unidirectional carbon fibers and epoxy matrix. Finally, by the measurement of the variation of attenuation versus the frequency, a linear model permits the computations in a large frequency range. Conclusions are carried out regarding the use of the LLW method in the inverse problem to recover elastic constants of composite materials.
本文给出了关于浸没在液体中的粘弹性正交各向异性板对入射平面波的反射和透射的理论与实验研究。考虑到层的各向异性，反射和透射系数用九个复弹性常数表示。与斯涅尔定律一致，层中产生的任何波都是体不均匀平面波。使用在各向同性情况下已经描述过的方法，反射和透射系数作为限制板的两个单一固/液界面处体不均匀平面波的反射和折射系数的函数而得到。通过这种方式，这些系数可以很容易地展开为德拜级数。此外，对于许多入射角和方位角，计算结果与由单向碳纤维和环氧树脂基体组成的复合材料的试验结果进行了比较。最后，通过测量衰减随频率的变化，一个线性模型允许在大频率范围内进行计算。得出了关于在反问题中使用低频波（LLW）方法来恢复复合材料弹性常数的结论。
