In the present investigation, free vibration of functionally graded material (FGM) skew plates under thermal environment is studied. Kinematics equations are based on the Reddy’s higher order shear deformation theory and a nine noded isoparametric Lagrangian element is adopted to mesh the plate geometry. The issue of C1 continuity requirement related to the assumed displacement field has been c...

Equations governing thermoelastic loss in vibrating thin plates are derived, generalizing Zener’s theory of thermoelastic loss in beams. The mechanism for the loss of mechanical energy is thermal diffusion caused by inhomogeneous deformation, flexure in thin plates. It is shown that a critical plate thickness, h∗, exists which separates two distinct types of response, which may be called therma...

ABSTRACT. The effectiveness of structural health monitoring via ultrasonic methods is seriously compromised by changing environmental conditions such as temperature. Variations in temperature can be spuriously identified as damage owing to thermal expansion or contraction of the material as well as changing of the wave propagation speed. This problem becomes even more serious when temperature c...

In recent years, ultrasonic methods have been developed that can be used to measure the mechanical stiffness of materials.1-5 In one such method, the velocity of a flexural plate wave, the lowest order antisymmetric Lamb mode, is measured as a function of frequency. Lamb waves arise from a coupling at the free boundaries between the shear waves and compressional waves in a plate structure.6 The...

Recently, an acoustic waveguide sensor based on multiple mode conversion of surface acoustic waves at the solid-liquid interfaces has been introduced for the concentration measurement of binary and ternary mixtures, liquid level sensing, investigation of spatial inhomogenities or bubble detection. In this contribution the sound wave propagation within this acoustic waveguide sensor is visualize...

Leaky Lamb waves are important research topics in the area of NDE and acoustic wave sensing technology. For waves propagating in a piezoelectric plate immersed in a fluid (dielectric or conductive), both mechanical and electrical loading effects present and result in phase velocity variation and wave attenuation. To quantitatively characterize these loading effects play an important role in var...

Although plate tectonics is well established, how a new subduction zone initiates remains controversial. Based on plate reconstruction and recent ocean drilling within the Izu-Bonin-Mariana, we advance a new geodynamic model of subduction initiation (SI). We argue that the close juxtaposition of the nascent plate boundary with relic oceanic arcs is a key factor localizing initiation of this new...

This work investigates transient heat conduction in a functionally graded plate (FGM plate) subjected to gradual cooling/heating at its boundaries. The thermal properties of the FGM are assumed to be continuous and piecewise differentiable functions of the coordinate in the plate thickness direction. A linear ramp function describes the cooling/heating rates at the plate boundaries. A multi-lay...