### ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

## 1aPA11. The range of existence of reflected homogeneous and surface waves
in elastic orthotropic materials.

**Sudhakar Nair
**

**
**
*Dept. of Mech., Mater., and Aerospace Eng., Illinois Inst. of Technol.,
Chicago, IL 60616
*

*
*
**Dimitrios A. Sotiropoulos
**

**
**
*Tech. Univ. of Crete, Chania 73100, Greece
*

*
*
Reflection of elastic waves from the free surface of orthotropic
incompressible materials is examined under plane strain conditions in a material
symmetry plane. Use of the physically allowable energy flux vectors in
conjunction with the propagation condition and the generalized Snell's law,
yields formulas for the range of existence of the different types of reflected
waves with respect to the two elastic parameters: the material orientation of
the free surface and the angle of incidence. It is the consideration of the
energy flux vectors that, in general, introduces the second elastic parameter
and enlarges the range for the existence of either two homogeneous shear plane
waves or one homogeneous and one supersonic surface wave. In the special case of
transverse isotropy, the above formalas yield a homogeneous shear wave and a
surface wave which diminishes when the angle of incidence is 45(degrees), the
wave-number vector coincides with the energy flux vector, and there enters only
one elastic parameter.