## 2aPAb7. Elastic interfacial waves in orthotropic interlayers.

### Session: Tuesday Morning, May 14

### Time: 10:15

**Author: Dimitrios A. Sotiropoulos**

**Location: Dept. of Mech., Mater. and Aerospace Eng., Illinois Inst. of Technol., Chicago, IL 60616 and Dept. of Eng. Sciences, Tech. Univ. of Crete, Chania 73100, Greece**

**Abstract:**

Elastic interfacial waves propagating along one of the planar boundaries
separating an orthotropic interlayer of arbitrary uniform thickness from an
orthotropic infinite surrounding solid are studied. The axes of material
symmetry of the two materials are aligned with one of the axes coinciding with
the propagation direction and another being perpendicular to the interfaces. The
dispersion equation is derived in explicit form yielding the interfacial phase
or group speed in terms of frequency, nondimensionalized with respect to the
interlayer thickness, and the elastic constants and mass densities of the
interlayer and the surrounding solid. Limiting cases of the dispersion equation
give the secular equation for interfacial (Stoneley) waves in two semi-infinite
orthotropic materials and the frequency equation for an orthotropic plate.
Analysis of the dispersion equation reveals several features. Under parameter
conditions which are defined propagation at low frequencies cannot occur. Also
material parameter combinations are found for which interfacial waves of
arbitrary wavelength as compared to the interlayer thickness cannot propagate.
Finally, the existence of standing waves as solutions of the bifurcation
equation, a special case of the dispersion equation, is defined with respect to
the parameters of the interlayer and the host material.

from ASA 131st Meeting, Indianapolis, May 1996