Diffraction of time-harmonic elastic waves by a cylindrical obstacle

1976 ◽  
Vol 32 (2) ◽  
pp. 97-144 ◽  
Author(s):  
T. H. Tan
2012 ◽  
Vol 131 (4) ◽  
pp. 2570-2578 ◽  
Author(s):  
Guangxin Tang ◽  
Laurence J. Jacobs ◽  
Jianmin Qu

2017 ◽  
Vol 33 (3) ◽  
pp. 035013 ◽  
Author(s):  
Elena Beretta ◽  
Maarten V de Hoop ◽  
Elisa Francini ◽  
Sergio Vessella ◽  
Jian Zhai

2015 ◽  
Vol 297 ◽  
pp. 62-83 ◽  
Author(s):  
Stéphanie Chaillat ◽  
Marion Darbas ◽  
Frédérique Le Louër

2012 ◽  
Author(s):  
Shen Wang ◽  
Maarten V. de Hoop ◽  
Jianlin Xia ◽  
Xiaoye Li

1972 ◽  
Vol 39 (3) ◽  
pp. 696-702 ◽  
Author(s):  
Adnan H. Nayfeh ◽  
Siavouche Nemat-Nasser

The WKB solution is derived together with the condition for its validity for elastic waves propagating into an inhomogeneous elastic medium. Large frequency expansion solution is also derived. It is found that the WKB solution agrees with that derived for large frequencies when the frequency approaches infinity. Some exact solutions are deduced from the WKB solution. Finally, we consider motions in medium which consists of a material with harmonic periodicity. The solution is obtained by means of a perturbation method. It is shown that, only when the wavelength of the incident wave is small compared with the periodicity-length of the material, the WKB solution constitutes a good approximation. When the wavelength is comparable with this periodicity-length, then, in certain special cases, the material cannot maintain time-harmonic waves; such harmonic waves are not “stable.” These and other solutions are discussed in detail.


Consider an infinite elastic solid containing a penny-shaped crack. We suppose that time-harmonic elastic waves are incident on the crack and are required to determine the scattered displacement field u i . In this paper, we describe a new method for solving the corresponding linear boundary-value problem for u i , which we denote by S. We begin by defining an ‘elastic double layer’; we prove that any solution of S can be represented by an elastic double layer whose ‘density’ satisfies certain conditions. We then introduce various Green functions and define a new crack Green function, G ij , that is discontinuous across the crack. Next, we use G ij to derive a Fredholm integral equation of the second kind for the discontinuity in u i across the crack. We prove that this equation always has a unique solution. Hence, we are able to prove that the original boundary-value problem S always possesses a unique solution, and that this solution has an integral representation as an elastic double layer whose density solves an integral equation of the second kind.


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