Free vibration characteristics of continuous grading fiber orientation (CGFO) beams resting on variable Winkler and two-parameter elastic foundations have been studied. The beam is under different boundary conditions and assumed to have arbitrary variations of fiber orientation in the thickness direction. The governing differential equations for beam vibration are being solved using Generalized...

in this paper, the stability of a functionally graded magneto-electro-elastic (fg-mee) micro-beam under actuation of electrostatic pressure is studied. for this purpose euler-bernoulli beam theory and constitutive relations for magneto-electro-elastic (mee) materials have been used. we have supposed that material properties vary exponentially along the thickness direction of the micro-beam. gov...

Earthquakes are vibrations induced by the rapid releases of large quantities energy from crustal movements. During seismic excitation, there kinetic energy, damping and strain acting on tunnel structure. Based indexes total releasable elastic dissipated this paper proposes three evaluation criteria for structure, which applied to optimization aseismic design cross-sectional shape material prope...

recently, a large amount of studies have been related to nonlinear systems with multi-degrees of freedom as well as continuous systems. the purpose of this paper is to optimize passive vibration absorbers in linear and nonlinear states for an euler-bernoulli beam with a nonlinear vibratory behavior under concentrated moving load. the goal parameter in the optimization is maximum deflection of t...

How does evolution grow bigger brains? It has been widely assumed that growth of individual structures and functional systems in response to niche-specific cognitive challenges is the most plausible mechanism for brain expansion in mammals. Comparison of multiple regressions on allometric data for 131 mammalian species, however, suggests that for 9 of 11 brain structures taxonomic and body size...

Havlicek et al. (Behavioral Ecology, 26, 1249-1260, 2015) proposed that increased attractiveness of women in hormonal states associated with high fertility is a byproduct (or “perceptual spandrel”) of adaptations related to between-women differences in sex hormones. A critical piece of their argument was the claim that between-women hormone-attractiveness correlations are stronger than correspo...

Coherent beam-beam tune shift of unsymmetrical beam-beam interactions was studied experimentally and numerically in HERA, where the lepton beam has such a large beam-beam parameter (up to xi(y) = 0.272 ) that the single-particle motion is locally unstable at the origin (closed orbit). Unlike the symmetrical case of beam-beam interactions, the ratio of the coherent beam-beam tune shift and the b...