In this article it is shown that for specific initial conditions an input beam injected in a Multimode Periodic Segmented Waveguides (MPSW) does not diffract and remains collimated all along the waveguide whereas a speckle like pattern is expected at the output of a multimode structure. This nonintuitive behavior can be explained with the help of ray and wave chaos properties. A modal analysis ...

Finite element formulations based generally on classical beam theories such as Euler-Bernoulli or Timoshenko. Sometimes, these two formulations could be problematic expressed in terms of restrictions of Euler-Bernoulli beam theory, in case of thicker beams due to non-consideration of transverse shear; phenomenon that is known as shear locking characterized the Timoshenko beam theory, in case of...

The aim of the study was to examine the deformation modes and also degradation of an adhesively bonded rectangular cross section beam used in the automotive body structure. The study included: (1) performing new experimental investigations on the three-point bend behavior of a rectangular cross section beam made by adhesive bonding method. (2) developing a finite element (FE) model to predict t...

This paper presents the study on influence external pressures on vibration of functionally graded materials thin-walled cylindrical shell supported. The functionally graded materials (FGMs) properties are graded in the thickness direction of the shell. FGMs are advanced composite materials, consisting of different types of materials, in which the properties shift continuously from one material ...

The control of lateral mode operation using a photonic crystal in a vertical-cavity surface-emitting laser ~VCSEL! is analyzed and confirmed experimentally. By controlling design parameters of the photonic crystal pattern, we have produced photonic crystal VCSELs that operate in higher order defect modes in addition to the fundamental defect mode. The transverse modal behavior is consistent wit...

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...

Recently, there has been renewed interest in methods and techniques of reducing the confusion and uncertainty associated with the morass of spurious, computational poles that result from the traditional over-determined equation set in modal parameter estimation processes. In this paper, sev eral additional mechanisms for providing a clear stabilization, or consistency, diagram are presented. Am...

in this paper, the modified euler-bernoulli beam model is presented to examine the influence of surface elasticity and residual surface tension on the critical force of axial buckling of nanotubes in the presence of rotary inertia. an explicit solution is derived for the buckling loads of microscaled euler beams considering surface effects. the size-dependent buckling behavior of the nanotube d...

Active vibration control of a smart flexible cantilever beam was studied by using mode theory and μ synthesis method. The actuator is piezoceramic patch, the sensor is strain gauge. The finite element method and experimental modal test was applied to obtain the dynamic model of the smart structure. Taking account into uncertainty of the external disturbance and measurement noise, and uncertaint...

Despite half a century of fuzzy sets and fuzzy logic progress, as fuzzy sets address complex and uncertain information through the lens of human knowledge and subjectivity, more progress is needed in the semantics of fuzzy sets and in exploring the multi-modal aspect of fuzzy logic due to the different cognitive, emotional and behavioral angles of assessing truth. We lay here the foundations of...