This paper deals with the experimental and numerical assessment of the vibration suppression of smart structures using piezoelectric shear actuators. Experimental results are presented for an adaptive sandwich cantilever beam that consists of aluminum facings and a core made of two piezoelectric shear actuators and foam. The electric Þeld is applied perpendicular to the poling direction of the ...

We present a micro-mechanical terahertz (THz) detector fabricated on silicon insulator (SOI) substrate and operating at room-temperature. The device is based U-shaped cantilever of micrometric size, top which two aluminum half-wave dipole antennas are deposited. This produces an absorption extending over the $\sim 2-3.5$THz frequency range. Due to different thermal expansion coefficients alumin...

Due to its simplicity, the parallel beam approximation (PBA) is commonly used in the analytical evaluation of the spring constant of V-shaped atomic force microscope (AFM) cantilevers. However, the point of contention regarding the validity of the PBA is as yet an unresolved issue, which has been exacerbated by some recent contradictory reports. In this paper, we present a detailed investigatio...

In this paper, modal analysis is carried out by using a Frenet frame-based shape measurement algorithm. This algorithm is validated through experiments conducted with a long slender, aluminum cantilever structure (65.625′′×2.0′′×0.125′′), which is instrumented with eight serially multiplexed fiber Bragg grating (FBG) sensors. The multiplexed FBG sensors measure the bending strain distribution a...

In this paper, a plane quadrilateral element with rotational degrees of freedom is developed. Present formulation is based on a hybrid functional with independent boundary displacement and internal optimum strain field. All the optimality constraints, including being rotational invariant, omitting the parasitic shear error and satisfying Fliepa’s pure bending test, are considered. Moreover, the...

The stress corrosion cracking (SCC) of different aging states for 7050 aluminum alloy in 3.5% sodium chloride aqueous solution has been studied by means of double cantilever beam (DCB) specimens, cathodic polarization, scanning electron microscope (SEM), transmission electron microscope (TEM) and time-of-flying second ion mass spectrometer (ToF-SIMS). The results showed that the susceptibility ...

The static pull-in instability of beam-type micro-electromechanical systems is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, c...

Selective Ga + ion implantation and miring by focused ion beam exposure and subsequent wet chemical etching is used to fabricate micro/nanomechanical elements in Si. Freestanding elements with a ~ 30 nm membrane thickness are made by controlled selective underetching between unexposed and exposed areas. Ultrahigh-frequency cantilever beams have been made with resonances in the tens of MHz range...

Vibration energy harvesting with piezoelectric materials currently generate up to 300 microwatts per cm2, using it to be mooted as an appropriate method of energy harvesting for powering low-power electronics. One of the important problems in bimorph piezoelectric energy harvesting is the generation of the highest power with the lowest weight. In this paper the effect of the shape and geometry ...

Intrinsic localized modes (ILMs) have been observed in micromechanical cantilever arrays, and their creation, locking, interaction, and relaxation dynamics in the presence of a driver have been studied. The micromechanical array is fabricated in a 300 nm thick silicon-nitride film on a silicon substrate, and consists of up to 248 cantilevers of two alternating lengths. To observe the ILMs in th...