This paper proposes a design for a precision positioning miniature walking robot using piezoelectric unimorph actuators. The theoretical working equations of a uniform piezoelectric unimorph beam are derived based on the linear piezoelectric relations, Hamilton’s principle, and Euler-Bernoulli beam equation. The modal superposition method is used to determine the response of the forced transver...

Beams, made in brittle materials like concrete or cement, show increasing crack development during their service life due to mechanical and environmental loadings. This local damage can often be translated into reduction of the local bending stiffness values. This paper presents a scanning method to identify the local stiffness values of thin beams using experimentally measured resonance freque...

We call piezoelectromechanical (PEM) truss beam a truss modular beam coupled with a transmission electrical line when the coupling is obtained by piezoelectric actuators which act as bars in the module and as capacitances in the electrical line. The truss module length is assumed negligible with respect to the considered wave lengths. The transmission electrical line is assumed continuously dis...

The absorption of light in transmissive optics cause a thermally induced effect known as thermal lensing. This effect provokes an often undesired change of a laser beam transmitted by the optic. In this paper we present a measurement method that allows us to determine thermal lensing in commonly used optical components. The beam influenced by the thermal lens is expanded into the eigenmodes of ...

Presenting structural damage detection problem as an inverse model-updating approach is one of the well-known methods which can reach to informative features of damages. This paper proposes a model-based method for fault prognosis in engineering structures. A new damage-sensitive cost function is suggested by employing the main concepts of the Modal Assurance Criterion (MAC) on the first severa...

This paper aims to introduce two new adaptive designs of vibration control systems. First is an absorber and the second is an isolator. Absorbers are used for suppressing unwanted vibrations, while isolators isolating them. Structural parameter changes and excitation directions significantly affect the behavior of the conventional passive controllers. A Tuned Stiffness Damper (TSD), stepper mot...

one of the main dichotomies in syntactic analyses deals with the distinction between lexical and functional categories. functional categories gain in stature as the generative grammar moves ahead. they come into play in explaining the derivation stages of phrases and sentences. the present study critically evaluates different approaches to the role and function of one of these functional catego...

The mathematical modeling of the large deflections for the cantilever beams leads to a nonlinear differential equation with the mixed boundary conditions. Different numerical methods have been implemented by various authors for such problems. In this paper, two novel numerical techniques are investigated for the numerical simulation of the problem. The first is based on a spectral method utiliz...

The classical purpose of optical fibres is delivery of either optical power, as for welding, or temporal information, as for telecommunication. Maximum performance in both cases is provided by the use of single-mode optical fibres. However, transmitting spatial information, which necessitates higher-order modes, is difficult because their dispersion relation leads to dephasing and a deteriorati...