Nonlinear free vibration analysis of double-walled carbon nanotubes (DWCNTs) embedded in an elastic medium is studied in this paper based on classical (local) Euler-Bernoulli beam theory. Using the averaging method, the nonlinear free vibration responses of DWCNTs are obtained. The result is compared with the obtained results from the harmonic balance method for single-walled carbon nanotubes (...

This paper studies the vibration energy harvesting characteristics of poled barium titanate (BT) unimorph cantilevers both analytically and experimentally. The unimorph cantilever consists of the BT layer and Cu shim, and the BT layer has sensing, grounding and driving electrodes. The output voltage of the cantilever excited by bending vibration was predicted by three dimensional finite element...

Free vibration of soil often occurs during earthquakes. Since the vibration caused by earthquake does not have (steady state harmonic vibration) continuity, the alluvium vibrates with its natural frequency between two natural seismic waves. This study evaluates the effect of piles on the period of free vibration of a soil layer using numerical method. In the first stage, using analytical equati...

This paper presents the modelling and analysis of a piezoelectric annular stator structure for a new in-situ dynamic balance regulator which is driven by the in-plane bending vibration of the stator. The mathematical model for the in-plane vibration is first developed using an analytical method to determine the theoretical excitation frequency. The excitation modes and structural parameters are...

In recent years, the use of castellated beams has increased significantly across all types structures. The beam is one several methods for reducing weight and cost steel in construction. this study, static dynamic behavior investigated via three-dimensional finite element method. primary objective study to investigate detail effect web opening shapes on displacement, stress values, free vibrati...

Bending-mode vibrations of carbon nanotube resonators were mechanically detected in air at atmospheric pressure by means of a novel scanning force microscopy method. The fundamental and higher order bending eigenmodes were imaged at up to 3.1 GHz with subnanometer resolution in vibration amplitude. The resonance frequency and the eigenmode shape of multiwall nanotubes are consistent with the el...

The thermal expansion effect of silicon nanowires (SiNW) in [100], [110] and [111] directions with different sizes is theoretically investigated. At low temperatures, all SiNW studied exhibit a thermal contraction effect due to the lowest energy of the bending vibration mode which has a negative effect on the coefficient of thermal expansion (CTE). The CTE in [110] direction is distinctly large...

We analyze coupled flexural vibration of two elastically and electrically connected piezoelectric beams near resonance for converting mechanical vibration energy to electrical energy. Each beam is a so-called piezoelectric bimorph with two layers of piezoelectrics. The 1D equations for bending of piezoelectric beams are used for a theoretical analysis. An exact analytical solution to the beam e...

UV resonance Raman studies of peptide and protein secondary structure demonstrate an extraordinary sensitivity of the amide III (Am III) vibration and the C(alpha)H bending vibration to the amide backbone conformation. We demonstrate that this sensitivity results from a Ramachandran dihedral psi angle dependent coupling of the amide N-H motion to (C)C(alpha)H motion, which results in a psi depe...