Transverse Edge Research Articles

Effect of Openings on Stresses in Rigid Pavements

A typical airport pavement section 12 in. (0.3 m) thick resting on a subgrade material have a modulus of elasticity, E°SsTD, equal to 8,400 psi (58 MN/mFRUS2TUTF) and treated as an elastic continuum is considered in this study. To limit the size of the slab, four cuts together with the corresponding boundary conditions were inserted at carefully chosen locations. Influence lines for the stresses f°SxTD and f°SyTD as well as stress distributions due to wheel loads were computed for critical locations of the load. These stresses were then compared with those obtained for an identical pavement section without opening under the same loading conditions. This comparison showed that a large increase in the value of maximum stress would result from the presence of the opening. A method is suggested to calculate the tensile forces around the opening. A simple formula for calculating the area of steel reinforcement required for a typical case has been derived accordingly effect of changing the length of the opening on the values of the stresses along its transverse edge was determined for the case of a point load.

Post-Buckling of Rectangular Plates with Various Boundary Conditions

SummaryThe Dynamic Relaxation method is used to analyse the post-buckling of flat rectangular plates. Extensive results are obtained for two types of problem in which the transverse edges are unloaded; in one case the transverse edges remain straight, in the other they are free to wave. Comparisons are made with alternative experimental and theoretical results. The potentiality of this approach to post-buckling problems is demonstrated by considering a variable thickness plate with mixed boundary conditions.

Modern Design of Concrete Pavements

Traffic studies on modern pavements and stress analysis with influence charts show that the critical stress location has changed from outside edges and corners to transverse joint edges. Design charts for the critical transverse edge stresses are presented and their use is shown in a design problem. Analysis of restrained contraction and warping stresses shows that these stresses do not influence thickness design. The new procedure reflects review of past and current fatigue research. The review justifies continued use of an endurance limit for concrete and a revised fatigue curve. Methods are presented for estimating total traffic, truck traffic, and the single and tandem axle loads needed for design. A comparison of alternate designs shows how the new procedure can be used to get low annual costs.

Transverse edge effects in linear induction motors

Currents in the secondary member of a linear induction motor flow in roughly elliptical paths. The secondary appears to have a resistivity greater than the natural value, and the cross-gap flux density peaks towards the edges of the stators. This phenomenon is known as the transverse edge effect. In most previous work, the edge effect has been allowed for only by the use of a resistivity-increase factor. This paper gives a more exact treatment.The method used takes account of flux leakage in the space between the stators and the secondary member, and in the secondary itself. Some approximation is necessary in the treatment of the machine end-turn flux. Equations are derived for the flux-density distribution in the air gap and for thrust, in each case as a function of stator current. Static-field measurements on two linear induction devices of different design, and with secondaries of different materials, showed good correlation for the two frequencies used, except at the extreme edges. In a simulated dynamic test using a rotary machine, calculated and measured field distributions and forces agreed well over the whole slip range

Stress concentration and load diffusion in rectangular panels with constant stress flanges

The stress concentration that occurs when load is diffused from a constant stress member into thin sheet is an important problem in the design of light weight structures. By using solutions in biharmonic polar-trigonometric series, the stress concentration can be effectively isolated so that highly accurate information necessary for design can be obtained. A method of analysis yielding high accuracy with limited effort is presented for rectangular panels with transverse edges free or supported by inextensional end ribs. Numerical data are given for panels with length twice the width.

Influence of Transverse Shear and Edge Condition on Nonlinear Vibration and Dynamic Buckling of Homogeneous and Sandwich Plates

Abstract : In a previous paper the variational equation of motion was applied to the nonlinear analysis of dynamic buckling of simply supported homogeneous (Timoshenko beam) and sandwich plates executing plane-strain motion. To investigate the influence of the edge condition and the interaction between the edge condition and transverse shear effect, the analysis is further extended in this paper to such plates with clamped edges. Results show that the transverse shear effect is much greater for sandwich than for homogeneous plates. They further show that the shear effect is always greater for the clamped than for the simply supported case and is in fact not entirely negligible even for a homogeneous plate if it is clamped. The same conclusions apply to nonlinear vibrations of such plates, which are also investigated. (Author)

Transient Motion of Circular Elastic Plates Subjected to Impulsive and Moving Loads

Forced transient motions of peripherally supported, circular, elastic plates are analyzed according to the classical plate theory. The Green's function for the plate is developed and used to construct solutions for concentrated impulsive loadings, suddenly applied loadings, and moving pressure-wave loadings. The boundary of the plate is considered to be elastically built-in in a manner that prevents transverse edge motion and provides a restoring edge moment linearly related to edge rotation. Thus, limiting cases include a clamped plate and a simply supported plate. Numerical results are included to illustrate the influence of structural and loading parameters on the dynamic response of the plate.

Forced Axisymmetric Motions of Circular Elastic Plates

Axisymmetric motions of a circular elastic plate are considered here according to the Poisson-Kirchhoff plate theory. A concentric ring loading of arbitrary time dependence is examined and used to construct solutions for a concentrated central load and for a uniform pressure loading. The boundary of the plate is considered to be elastically built-in in a manner that prevents transverse edge motion and provides a restoring edge moment linearly related to edge rotation. Thus, limiting cases are a clamped plate and a simply supported plate. Finally, a discussion relating this work to the integral-transform approach of Sneddon is presented to enable physical interpretation and generalization of his approach.

Norslund. En kystboplads fra ældre stenalder

Norslund. En kystboplads fra ældre stenalder

Non‐linear Bending of an Annular Plate by Transverse Edge Forces

Journal of Mathematics and PhysicsVolume 43, Issue 1-4 p. 275-303 Article Non-linear Bending of an Annular Plate by Transverse Edge Forces V. G. Hart, V. G. Hart Computing Machine Laboratory the University Manchester, England Computing Machine Laboratory the University Manchester, EnglandSearch for more papers by this authorD. J. Evans, D. J. Evans Computing Machine Laboratory the University Manchester, England Computing Machine Laboratory the University Manchester, EnglandSearch for more papers by this author V. G. Hart, V. G. Hart Computing Machine Laboratory the University Manchester, England Computing Machine Laboratory the University Manchester, EnglandSearch for more papers by this authorD. J. Evans, D. J. Evans Computing Machine Laboratory the University Manchester, England Computing Machine Laboratory the University Manchester, EnglandSearch for more papers by this author First published: April 1964 https://doi.org/10.1002/sapm1964431275Citations: 10AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume43, Issue1-4April 1964Pages 275-303 RelatedInformation

Shear Buckling of Clamped and Simply-Supported Infinitely Long Plates Reinforced by Closed-Section Transverse Stiffeners

SummaryThe paper presents a solution to the buckling of infinitely long plates when they are reinforced by transverse stiffeners possessing both torsional and flexural rigidity. The cases of both edges being clamped and simply-supported are dealt with. Numerical results are presented for the ratio of torsional rigidity to flexural rigidity as obtained with a thin-walled circular tube. When the stiffeners are completely rigid, in which case the individual panels are clamped along the transverse edges, the results obtained are in agreement with existing solutions for isolated rectangular plates.

Elastic Instability of a Stringer on Thin Sheets

Figure 1 illustrates a load diffusion problem which occurs in ship structural design, and which may also be relevant to aircraft structures. A load applied to one end of a stringer is diffused into the attached sheet and eventually reacted by shearing forces at the longitudinal edges. The transverse edges of the sheet and the other end of the stringer are not loaded.Various methods, which differ in their assumptions regarding stresses and displacements in the sheet, are available for tackling this problem. For calculating the distribution of load or stress in the stringer it makes little difference which method is used. The “finite stringer” method of reference (1) is the simplest and should be sufficiently accurate for most cases.

Elastic Instability of Stiffened Sheet under Compression Reacted by Shear

Figure 1 illustrates a structural problem which occurs in naval architecture, and which may also be of interest in the structural design of aircraft. Compressive loading is applied to one transverse edge of a stiffened flat sheet and reacted, not by equal compressive loads on the opposite transverse edge, but by shear forces along the two longitudinal edges. These shear forces, and the complementary shear forces acting on the transverse edges, arise from the connection of the stiffened sheet to adjacent structure. This situation arises, for example, at a ship's transverse bulkhead. The lower edge of the bulkhead is subjected to vertical loads applied by the ship's bottom structure, and these loads are transmitted upwards and outwards to the vertical edges of the bulkhead, thence to be diffused into the side shell plating.

Slot admittance data at Kaband

Admittance data on transverse edge slots in RG-96/U waveguide can be obtained by a technique called the moving lossy short technique. By this technique the radiation attenuation of a test section of identical slots can be determined. It is then possible to specify both the slot inclination angle and the slot depth of cut required to yield any conductance with in the range of measurements. These data were used to design an experimental 30-slot array with a 25-db Taylor aperture distribution. This array was successful, yielding sidelobes near -23 db. Subsequently, the same data were used in designing an 8-foot array with 432 edge slots having the same aperture distribution. This array had a half-power beamwidth of 14 minutes and sidelobes of the order of -24 db. These results compared favorably with design objectives.

Stability of rectilinear plates

AbstractIt is shown that the critical thrust for the stability of a simply supported rectilinear plate under the combined action of transverse load and edge thrust corresponds to the least eigen value for the transverse vibrations of a clamped membrane having the same boundary as that of the plate.

O aparelho Saltatório do Halticíneo Homophoeta sexnotata Har. (Coleoptera)

Descreveu-se o mecanismo saltatório do Halticíneo Homophoeta sexnotata. O aparelho se encontra localizado no fêmur e consta de uma placa cuticular arqueada, em forma de S, e, de uma placa menor, triangular. Tôdas as placas representam modificações dos tendões do abdutor e flexor da tíbia e mantêm ainda ligação com os mesmos. Pela colaboração das duas placas acumula-se uma forte tensão no tendão do abdutor (músculo saltatório). A tíbia não se pode esticar pois a placa trinagular fica presa numa cavidade da parede do fêmur. Apenas no momento da maior contração do abdutor a placa curvada força a saida da placa triangular do seu ponto de apóio. Desta maneira o forte músculo abdutor da tíbia exerce tôda a sua força, de uma só vez, sôbre a articulação da mesma, dando ao Coleóptero um forte impulso para saltar. O órgão é encontrado em grande número dos Halticíneos. em homenagem ao grande entomólogo brasileiro PROF. DR. ANGELO DA COSTA LIMA dei ao órgão o nome de ÓRGÂO DE COSTA LIMA.