Nonlinear effects in vibration responses are investigated for the undamaged composite plate and the composite plate with a delamination. The analysis is focused on higher harmonic generation in vibration responses for various excitation amplitude levels. This effect is investigated using the triple correlation technique. The dynamics of composite plate was modelled using two-dimensional finite ...

This paper focuses on the relation between the vibration modes of mechanical systems and the modes computed through a blind source separation technique called independent component analysis (ICA). For free and random vibrations of weakly damped systems, a one-to-one relationship between the vibration modes and the ICA modes is demonstrated using the concept of virtual source. Based on this theo...

This paper reviews shearography and its applications for testing of composite structures. Shearography is a laser-based technique for fullfield measurement of surface deformation. Unlike holography, it does not require special vibration isolation; hence it can be employed in field/factory environments. The technique has already received considerable industrial acceptance for nondestructive test...

In this paper the wavelet packet transform is used for processing of rolling element bearing fault signals. The effectiveness of the envelope analysis technique is combined with the flexibility of the wavelet packet transform, helping in the minimization of interventions by the end user. According to the proposed method, a time-frequency decomposition of a vibration signal is provided and the c...

Bending, buckling and vibration behaviors of nonlocal Timoshenko beams are investigated in this research using a variational approach. At first, the governing equations of the nonlocal Timoshenko beams are obtained, and then the weak form of these equations is outlined in this paper. The Ritz technique is selected to investigate the behavior of nonlocal beams with arbitrary boundary conditions ...

Abstract—This paper has been investigated a technique that predicts the performance of a bar-type unimorph piezoelectric vibration actuator depending on the frequency. This paper has been proposed an equivalent circuit that can be easily analyzed for the bar-type unimorph piezoelectric vibration actuator. In the dynamic analysis, rigidity and resonance frequency, which are important mechanical ...

Introduction: Local anesthesia (LA) is essential for most oral and maxillofacial procedures. It is important that clinicians obtain adequate pain control during not only dental treatments but also LA injection. Materials and methods: This study evaluated the effects of vibration on pain and anxiety levels during LA injection in 50 patients using a visual analog scale (VAS) and Spielberger’s Sta...

Nanometer vibration analysis of a target has been demonstrated by a self-aligned optical feedback vibrometry technique that uses a laser-diode-pumped microchip solid-state laser. The laser output waveform, which was modulated through interference between a lasing field and an extremely weak (<- 100-dB) frequency-modulated (FM) feedback field, was analyzed by the Hilbert transformation to yield ...

Devices that harvest electrical energy from mechanical vibrations have the problem that the frequency of the source vibration is often not matched to the resonant frequency of the energy harvesting device. Manufacturing tolerances make it difficult to match the Energy Harvesting Device (EHD) resonant frequency to the source vibration frequency, and the source vibration frequency may vary with t...

The current research talks about a designed accelerometer system which is able to measure every type of mechanical vibration. The applied vibration in this survey is called seismic wave. Then the measured wave by this novel system is transf ormed to a specif ic function using spline interpolation. This explicit function can be used as a reference signal in the technique PWM to be made in curren...