Reflection of Longitudinal Wave in the Micropolar Elasticity with Voids

By considering no more interaction between wryness tensor and change in voids volume fraction in the materials, the reflection problem of plane longitudinal waves at a free boundary of micropolar elastic materials with voids has been investigated. We have obtained the amplitude and energy ratios of reflected waves for the incident longitudinal wave by using appropriate boundary conditions. The effect of void parameters in the nondimensional wavenumber, amplitude and energy ratios are computed numerically for the particular material’s model.

A plane strain problem in the theory of elastic materials with voids

This article is concerned with the linear theory of elastic materials with voids. With respect to the classical theory of elasticity, this model is characterized by four independent kinematic variables: the displacement field [Formula: see text][Formula: see text] and the change in volume fraction [Formula: see text]. First, we present the field equations in the equilibrium theory and derive the equations of the plane strain problem. Then, the problem of a cylindrical rigid inclusion in an infinite body is investigated. The results are obtained in closed form. The solution can be considered as a generalization of the corresponding problem in the classical theory of elasticity. The displacement field and the stresses are expressed by mean of explicit formulas. The maximum tensile stress and the stress concentration factor are calculated.

Effect of mechanical relaxation time in elastic materials with voids

The effect of mechanical relaxation time in the elastic wave propagation in elastic materials with voids is investigated. The phase speed and the attenuation coefficients are obtained and observed the effect of mechanical relaxation time. The phenomenon of reflection of elastic waves due to the incident waves from a plane boundary of elastic materials with voids is studied. The amplitude and energy ratios of the reflected waves are obtained. Numerically these ratios, phase speeds and the corresponding attenuation coefficients are computed for a particular model and the effect of mechanical relaxation time is discussed.

Axisymmetric Vibration of Piezo-Lemv Composite Hollow Multilayer Cylinder

Axisymmetric vibration of an infinite piezolaminated multilayer hollow cylinder made of piezoelectric layers of 6 mm class and an isotropic LEMV (Linear Elastic Materials with Voids) layers is studied. The frequency equations are obtained for the traction free outer surface with continuity conditions at the interfaces. Numerical results are carried out for the inner, middle, and outer hollow piezoelectric layers bonded by LEMV (It is hypothetical material) layers and the dispersion curves are compared with that of a similar 3-layer model and of 3 and 5 layer models with inner, middle, and outer hollow piezoelectric layers bonded by CFRP (Carbon fiber reinforced plastics).