In this paper, a size-dependent formulation for the Bernoulli-Euler beam is developed based on a new model of couple stress theory presented by Hadjesfandiari and Dargush. The constitutive equation obtained in this new model, consists of only one length scale parameter that is capable of capturing the micro-structural size effect in predicting the mechanical behavior of the structure. Having on...

There are derived sufficient conditions for the posltivity of Green's function of two-point boundary value problems of the fourth order. The results are gained by applying a theorem on Inverse-monoton o operators In partially ordered spaces. In the case of an example (beam on elastic support), the derived conditions are also necessary.

purpose: regarding the role of the observer in cybernetics, this paper aims to investigate the evolution of knowledge. it states the philosophical foundations of four types of cybernetics in order to reveal the necessity of these approaches in knowledge and information science. methodology: review and analysis of published resources findings: the observer performs different roles in various ord...

We investigate the second-harmonic generation of the nth-order Bessel beam in the nonlinear medium. The analysis is based on the Khokhlov-Zabolotskaya-Kuznetsov wave equation under the second-order approximation in nonlinear acoustics. The theory indicates that for an nth-order Bessel beam, the second-harmonic beam is nearly diffraction-free in the radial direction and behaves as a Bessel beam ...