Abstract
It is well known that the major contribution to an impact response of solid material is the surface waves propagating along a free edges of the plate materials. Then, the subject is focused to the characteristic waves relating to a fiber reinforced composite material. The stress free surface is the cross section generated in mechanical production process by cutting at off-angle to a material symmetric axis. The analytical results show that the cutting angle and fiber volume fraction of composite materials affect the path and direction of particle motion considerably as well as the phase velocity. In the analysis, classical effective modulus theory was used because the wave length is quite large comparing with the geometrical dimensions of composites in most practical cases. The elastic constants are set under the plane stress condition. Numerical calculation was carried out for a glass fiber reinforced epoxy resin matrix composite; Young’s modulus Ef = 73.1[GPa], Em = 3.45[GPa], Poisson ratio vf = 0.22, vm = 0.35, density Df = 2.6[g/m3], Dm = 1.15[g/m3], and miss-alignment factor k = 0.95. The graphs have been made by selecting the parameters of off-angle and volume fraction of fiber. The numerical results show us the some interesting phenomena. For example, the characteristic Rayleigh waves studied are the different ones from the conventional ones. The Rayleigh wave propagating along the oblique cut surface, is composed of two different body waves, quasi-longitudinal P-wave and quasitransverse S-wave. Furthermore, phase plane directions of the body waves are different each other, and they are not orthogonal to the free surface any more. These characteristic results provide important information for analyses of dynamic response of a fiber reinforced composite material.
