this paper presents new sensitivity-based methods for detection of structural damage using incomplete noisy modal data. these methods are based on the first-order derivative of modal parameters. changes of natural frequency do not usually provide spatial information on the structural damage. they are also not sensitive to the local damage. in this paper, a new sensitivity function is proposed u...

Flow induced vibration and smart control of elastically coupled double-nanotube-systems (CDNTSs) are investigated based on Eringen’s nonlocal elasticity theory and Euler-Bernoulli beam model. The CDNTS is considered to be composed of Carbon Nanotube (CNT) and Boron-Nitride Nanotube (BNNT) which are attached by Pasternak media. The BNNT is subjected to an applied voltage in the axial direction w...

We integrated a piezoelectric sensing layer lamina containing liquid crystals (LC) and spiropyran (SP) in a LC/SP mixture to create an optically reconfigurable modal sensor for a cantilever beam. The impedance of this LC/SP lamina was decreased by UV irradiation which constituted the underlying mechanism to modulate the voltage externally applied to the piezoelectric actuating layer. Illuminati...

This paper describes an analytical and experimental investigation of the property of modal disparity in a vibrating structure. For a given structure, the concept of modal disparity describes the structure’s ability to generate significant changes in the mode shapes by some type of on-the-fly structural modification. In the present study we consider a vibrating beam that experiences a controlled...

Finding the thermoelastic damping in a vibrating body, for the most general case, involves the simultaneous solving of the three equations for displacements and one equation for temperature (called the heat equation). Since these are a set of coupled nonlinear partial differential equations there is considerable difficulty in solving them, especially for finite geometries. This paper presents a...

Most Structural Health Monitoring (SHM) techniques are based on the variation of modal properties of structures. Modal analysis is established under the assumption that the structure behaviour is linear. However, the presence of non-linearities (local or global, smooth or strong) can affect the dynamic properties of the structure. Most of techniques to detect non-linear behaviour in structural ...

Abstract Modality is a generic concept of wave-optics at the basis optical information and communications. One challenges photonics technologies based on orbital angular momentum consists in production modal content for both azimuthal radial degrees freedom. This basically requires shaping complex amplitude an incident light beam, which usually made up from adaptive spatial modulators or bespok...