A Modified Wedge Method for exciting Shear Modes in Isotropic Media
A Modified Wedge Method for exciting Shear Modes in Isotropic Media
复制标题
各向同性介质中激发剪切模式的改进楔法
作者：
B. Rao;P. Rao
Bhagavantam 和 Bhimasenachar1 开发的楔形法在测定固体弹性常数方面非常有用。但经常发现很难激发和识别传输最大值的剪切模式，因为它们非常弱并且与楔块的寄生频率具有相同的强度数量级。然而，有人指出，如果使用小薄样本，由于边缘耦合，剪切模式也可能被激发，尽管很弱。最近3，有报道称，在粗粒且成分不均匀的岩石中不能激发剪切模式。这里提出的方法描述了楔形法的简单修改，用于仅激励和识别各向同性介质中的剪切模式，从而克服了普通楔形法固有的困难。
THE wedge method developed by Bhagavantam and Bhimasenachar1 has been very useful in the determination of elastic constants of solids. But very often it is found to be difficult to excite and identify the shear modes for the transmission maxima, as they are very weak and are of the same order of intensity as the spurious frequencies of the wedge. However, it has been pointed out2 that, if small thin specimens are used, shear modes could also be excited, although feebly, due to edge coupling. Recently3, it has been reported that shear modes cannot be excited in rocks which are coarse-grained and heterogeneous in composition. The method presented here describes a simple modification of the wedge method for exciting and identifying easily only the shear modes in isotropic media and thus overcoming the difficulties inherent in the normal wedge method.