Search results for "Transverse plane"
showing 10 items of 285 documents
Shear strength of High-strength concrete beams: modeling and design recommendations
2014
Abstract In the present paper, the flexural and the shear resistance of high strength reinforced concrete (HSC) beams with longitudinal bars, in the presence of transverse stirrups is analyzed both theoretically and experimentally. The experimental researches here presented are parts of previous researches carried out by the author. Researches refer to HSC beams with high percentages of steel bars failing in shear and in flexure. From the analytical point of view, a model based on the evaluation of the resistance contribution due to beam and arch actions including bond splitting and concrete crushing failure modes is developed and presented. The model was verified against available experime…
Dynamic railroad inspection using the laser-air hybrid ultrasonic technique
2006
Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave laser-generation apparatus can be metres away from the interrogated surface while air-coupled detection standoff can be on the order of several centimetres. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detection te…
Tramway Track: A New Approach for Measuring the Transverse Profile of Worn-Out Rails
2012
Abstract Monitoring the wear condition of the tramway superstructure is one of the key points to guarantee an adequate safety level of the light rail transport system. The purpose of this paper is to suggest a new non-conventionalprocedure for measuring the transverse profile of rails in operation by means of image-processing technique. This methodological approach is based on the “information” contained in high-resolution photographic images of tracks and on specific algorithms which allow to obtain the exact geometric profile of the rails and therefore to measure the state of the rail-head extrados wear.
Laser-air hybrid ultrasonic technique for dynamic railroad inspection applications
2005
The Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave laser-generation apparatus can be metres away from the interrogated surface, while air-coupled detection stand-off can be on the order of several centimetres. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detect…
Twisting and buckling: A new undulation mechanism for artificial swimmers
2012
Among the various locomotion strategies of the animal kingdom, the undulation locomotion is of particular interest for biomimetic applications. In this paper, we present an artificial swimmer set into motion by a new and non-trivial undulation mechanism, based on the twisting and buckling of its body. The swimmer consists of a long cylinder of ferrogel which is polarized transversely and in opposite directions at each extremity. When it is placed on a water film and submitted to a transverse oscillating magnetic field, the worm-like swimmer undulates and swims. Whereas symmetry breaking is due to the field gradient, the undulations of the worm result from a torsional buckling instability as…
Orientation and Crystallinity Measurements in Film Casting Products
2003
Film casting experiments were carried out with iPP under processing conditions causing the crystallization process to occur under orienting flow. Draw ratio and cooling rates were changed by varying mass flow rates and die thickness. The effect of processing conditions on film crystallinity was investigated by combining WAXS and FT-IR transmission methods, while orientation of both phases was measured by IR dichroism (according to Fraser's method) and successfully compared to birefringence measurements on final films. Crystallinity appears to be almost insensitive to draw ratio and cooling rate. Moreover the crystallinity profile turned out to be also constant along the transverse film dire…
Thermoconvective instabilities in an inclined porous channel heated from below
2011
Abstract The thermoconvective instability in an inclined rectangular channel filled with a fluid saturated porous medium and heated from below with a uniform flux is investigated. A stationary parallel buoyant flow with a linear temperature change in the transverse direction is considered. The linear stability to transverse and longitudinal roll disturbances of this basic state is examined. The thermoconvective instability onset of transverse rolls occurs when the Darcy–Rayleigh number exceeds a critical value, that increases with the inclination angle. The critical Darcy–Rayleigh number is discontinuous at the inclination angle 23.4749° above the horizontal. It is shown that, when the incl…
CFD prediction of shell-side flow and mass transfer in regular fiber arrays
2021
Numerical simulations were conducted for fully developed, steady-state flow with mass transfer in fiber bundles arranged in regular lattices. The porosity was 0.5 and the Schmidt number 500. Several combinations of axial flow, transverse flow and flow attack angles in the cross-section plane were considered. The axial and transverse Reynolds numbers Rez , ReT were made to vary from 10(^−4) to 10(^2). Concentration boundary conditions, and the definition of an average Sherwood number, were addressed. Results for the hydraulic permeability were compared with the literature. Both hexagonal and square lattices were found to be hydraulically almost isotropic up to transverse flow Reynolds number…
Lie algebra on the transverse bundle of a decreasing family of foliations
2010
Abstract J. Lehmann-Lejeune in [J. Lehmann-Lejeune, Cohomologies sur le fibre transverse a un feuilletage, C.R.A.S. Paris 295 (1982), 495–498] defined on the transverse bundle V to a foliation on a manifold M, a zero-deformable structure J such that J 2 = 0 and for every pair of vector fields X , Y on M: [ J X , J Y ] − J [ J X , Y ] − J [ X , J Y ] + J 2 [ X , Y ] = 0 . For every open set Ω of V, J. Lehmann-Lejeune studied the Lie Algebra L J ( Ω ) of vector fields X defined on Ω such that the Lie derivative L ( X ) J is equal to zero i.e., for each vector field Y on Ω : [ X , J Y ] = J [ X , Y ] and showed that for every vector field X on Ω such that X ∈ K e r J , we can write X = ∑ [ Y ,…
Quasi-free electron scattering in a relativistic model of the nucleus
1989
Longitudinal and transverse response functions of quasi-free electron scattering have been calculated in mean field approximation for a relativisticσ-ω model, including non-linearities in theσ-field. As a consequence of the completely consistent and fully relativistic treatment of wave functions and current operators, gauge invariance is perfectly satisfied throughout the calculation. The results indicate that models with the same nuclear bulk properties lead to similar response functions within 10%. Our results agree with the experimental data for12C and238U, but cannot describe the longitudinal response in the Ca-Fe region. Predictions for208Pb are given for comparison with future experim…