in this paper a new strategy is proposed to design a fixed-structure robust controller for a flexible beam.  robust controller designed by the conventional  loop­ shaping method is not appropriate for a beam because of its high order and complicated form. fixed-structure  loop shaping control in conjunction with particle swarm optimization (pso)algorithm  is used to overcome this drawback. the ...

In this paper, the free vibration analysis of sandwich micro beam with piezoelectric layers based on the modified couple stress and surface elasticity theories are investigated. The Hamilton’s principle is employed to derive the sandwich micro beam with piezoelectric based on modified couple stress theory incorporating with Gurtin- Murdoch surface theory. The generalized differential quadrature...

We introduce a new method to propagate uncertainties in the beam shapes used to measure the cosmic microwave background to cosmological parameters determined from those measurements. The method, called markov chain beam randomization (MCBR), randomly samples from a set of templates or functions that describe the beam uncertainties. The method is much faster than direct numerical integration ove...

The damage identification study presented in this article leveraged a full-scale sub-component experiment conducted in the Charles Lee P owell Structural Research Laboratories at the University of California, San Diego. As a payload project attached to a quasi-static test of a full-scale composite beam, a high-quality set of lowamplitude vibration response data was acquired from the beam at var...

In this paper the conjugate gradient (CG) method is employed for identifying the parameters of crack in a functionally graded beam from natural frequency measurement. The crack is modeled as a massless rotational spring with sectional flexibility. By using the Euler-Bernoulli beam theory on two separate beams respectively and applying the compatibility requirements of the crack, the characteris...

Based on the theory for the turbulence and the Rytov method, the propagation formulas of the scintillation index and the mean square angle-of-arrival fluctuation for the beam propagation in atmospheric turbulence have been derived respectively. The propagation properties of the two turbulence effects have been investigated, and the effects of the characteristic parameters of turbulence and the ...

It is shown that three-dimensional nonparaxial beams are described by the oblate spheroidal exact solutions of the Helmholtz equation. For what is believed to be the first time, their beam behavior is investigated and their corresponding parameters are defined. Using the fact that the beam width of the family of paraxial Gaussian beams is described by a hyperbola, we formally establish the conn...

Proton Source and LEBT At CEA/Saclay the SILHI (Source des Ions Légères a Hautes Intensitées) is operating since 1996 and its nominal beam parameters fit to the needs of the FAIR proton linac. In December 2005 beam emittances for various source and LEBT parameters were measured during a joint CEA/GSI/IAP campaign. Its evaluation in 2006 followed by additional measurements on space charge compen...

A semi-analytical method is used to study the effects of the multi vibration absorbers on the nonlinear functionally graded (FG) Euler-Bernoulli beam subjected to periodic load. The material properties of the beam are assumed to be continuously graded in the thickness direction. The governing equations of functionally graded beam are obtained based on the Hamilton's principle and these equation...