The present paper aims at analytically evaluating the natural frequencies of cracked slender masonry elements. problem is dealt with in framework linear perturbation, and small oscillations structure are studied under loaded conditions, after equilibrium for permanent loads has been achieved. A beam element made masonry-like material considered, some explicit expressions beam's fundamental freq...

Twisted relativistic light pulses with a strong torque and an ultrahigh orbital angular momentum density can in principle be created by shining light pulses onto a specially design thin metal foil, report scientists in China. Theoretical analysis and simulations by Yin Shi and co-workers at the Shanghai Institute of Optics and Fine Mechanics predict that when intense pulses with planar wavefron...

Abstract. Beamlike structures are commonly studied via 1D beam models, which more efficient than 3D finite element methods, but do not permit accurate predictions of stresses in non-prismatic cases. Despite the progress made their modeling, either direct approaches or dimensional reductions from formulations, analytical prediction and strains beamlike yet elements, with non-uniform properties b...

In this article, the size effect on the dynamic behavior of a simply supported multi-cracked microbeam is studied based on the Modified Couple Stress Theory (MCST).  At first, based on MCST, the equivalent torsional stiffness spring for every open edge crack at its location is calculated; in this regard, the Stress Intensity Factor (SIF) is al...

The presented work introduces a numerical parametric study on the crack propagation direction under mixed-mode conditions (mode I + II). It is conducted for the geometry of an eccentric asymmetric fourpoint bending of a single edge notched beam specimen; various levels of mode-mixity are ensured by modifications in the crack length and crack eccentricity. The direction of crack propagation is e...

A new type of highly-directional ultrasonic range sensor is designed, fabricated, and tested in this paper. To improve directivity, the parametric acoustic array, a nonlinear effect of media between two intensive waves, is applied to an ultrasonic range sensor. Additionally, a new type of the stepped-plate transducer is applied for generating high amplitude waves consisting of two frequencies. ...

Determining the neural correlates of loss of balance during walking could lead to improved clinical assessment and treatment for individuals predisposed to falls. We used high-density electroencephalography (EEG) combined with independent component analysis (ICA) to study loss of balance during human walking. We examined 26 healthy young subjects performing heel-to-toe walking on a treadmill-mo...

In the present paper, computations of mixed mode stress intensity factor (SIF) variations along the crack front, and fatigue-crack-growth simulations, in cracked I-beams, considering different load cases and initial crack configurations, are carried out by employing the three-dimensional SGBEM (Symmetric Galerkin Boundary Element Method)–FEM (Finite Element Method) Alternating Method. For mode-...