Secondary Stresses in Airship Hull Structures

1927 ◽  
Vol 31 (204) ◽  
pp. 1073-1109
Author(s):  
J. F. Baker
Keyword(s):  
Cross Section ◽  
External Load ◽  
Structural Engineering ◽  
Secondary Stress ◽  
Rigorous Definition ◽  
The Cross ◽  
Definition Of ◽  
Redundant Structure ◽  
Ball Joints ◽  
External Loads

In no branch of structural engineering is there a rigorous definition of the term “secondary stress.”If the primary stresses in a structure are determined, that is, the stresses in the members due to an external load system, assuming that all the members are joined together by perfect pin- or ball-joints, then the secondary stresses are in general taken to be the additional stresses due to the rigidity of the actual joints used in practice.In such a highly redundant structure as an airship hull the labour involved, in determining even the primary stresses, precludes the use of the normal methods of stressing. It is usual to make use of generalised methods which give approximate results. These generalised methods imply that the external loads are applied to the structure in a certain distribution. Though this is rarely achieved, yet the results obtained are in most cases sufficiently accurate if suitable bracing is supplied to redistribute the external loads over the cross-section; the effect of the initial wrong distribution being then merely local.

City Occupancy and Road Capacity Model

2014 ◽  
Vol 1044-1045 ◽  
pp. 1538-1540 ◽  
Author(s):  
Yi Lin Fan ◽  
Bei Chen Cheng ◽  
Li Li Cao ◽  
Kun Cheng Huang
Keyword(s):  
Cross Section ◽  
Road Traffic ◽  
The Road ◽  
Road Capacity ◽  
Traffic Capacity ◽  
Capacity Model ◽  
The Cross ◽  
Definition Of ◽  
The Impact ◽  
Accident Case

In this paper, we study the impact of city driveway occupancy on the urban road traffic capacity. Through the analysis of the scene of an accident case, we gained the vehicle statistics within a cross section in unit time and then did calculation and simulation. The work is concluded as a reasonable model of vehicle queue relationship evaluation.First, on the base of the definition of traffic capacity, statistics of the cars in the cross section before the accident, during the accident and after the accident have been respectively acquired in unit time (1 min). Then we employ Matlab to do the interpolation fitting, drawing the change of actual capacity of the road from the beginning time of an accident to the time when traffic resumes. The work comes to a conclusion that the change of the capacity at the cross section has a pattern of periodic fluctuation.

THE RENNER MONOIDS AND CELL DECOMPOSITIONS OF THE SYMPLECTIC ALGEBRAIC MONOIDS

2003 ◽  
Vol 13 (02) ◽  
pp. 111-132 ◽  
Author(s):  
ZHENHENG LI ◽  
LEX E. RENNER
Keyword(s):  
Cross Section ◽  
Borel Subgroup ◽  
Unit Group ◽  
Admissible Sets ◽  
Cell Decompositions ◽  
A Cell ◽  
Direct Definition ◽  
The Cross ◽  
Definition Of ◽  
Renner Monoid

In this paper we explicitly determine the Renner monoid ℛ and the cross section lattice Λ of the symplectic algebraic monoid MSpn in terms of the Weyl group and the concept of admissible sets; it turns out that ℛ is a submonoid of ℛn, the Renner monoid of the whole matrix monoid Mn, and that Λ is a sublattice of Λn, the cross section lattice of Mn. Cell decompositions in algebraic geometry are usually obtained by the method of [1]. We give a more direct definition of cells for MSpn in terms of the B × B-orbits, where B is a Borel subgroup of the unit group G of MSpn. Each cell turns out to be the intersection of MSpn with a cell of Mn. We also show how to obtain these cells using a carefully chosen one parameter subgroup.

Influence of a Metal Beam of a Corrugated Wall Geometrical Parameters on Size and Nature of Internal Tension Distribution

2018 ◽  
Vol 931 ◽  
pp. 247-251 ◽  
Author(s):  
Aleksey O. Lukin ◽  
Vadim Y. Alpatov
Keyword(s):  
Cross Section ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Tension Distribution ◽  
Relevant Task ◽  
Construction Mechanics ◽  
Geometrical Form ◽  
The Cross ◽  
Corrugated Wall ◽  
Definition Of

Nowadays a concept of a beam with a corrugated wall in construction mechanics does not exist. Such designs do and they are used in construction. Definition of the intense deformed condition of a beam with a corrugated wall is a relevant task. In this article the task of tension distribution nature assessment in the cross section of a beam in a corrugation height variation was discussed. The task was solved in the course of the numerical experiments with application of the finite element method (FEM). The problem was solved for beams with different shapes of the lines forming a corrugation. It was established that the geometrical form of a corrugation practically didn't influence the nature of tension distribution on a beam section and tension distribution on the cross section of beams with a corrugated wall depends generally on the corrugation height relation to its width.

On the Bending Problem of Prismatical Beam by Terminal Transverse Load

1965 ◽  
Vol 32 (1) ◽  
pp. 210-211 ◽  
Author(s):  
Toma Leko
Keyword(s):  
Turbine Blade ◽  
Cross Section ◽  
Arbitrary Constant ◽  
Transverse Load ◽  
Shearing Stress ◽  
Shear Center ◽  
Blade Vibration ◽  
Bending Force ◽  
The Cross ◽  
Definition Of

Although the Saint-Venant solution on the bending problem of a prismatical beam by terminal transverse load is presented in all the literature on applied elasticity, the arbitrary constant in that solution has not been determined adequately. The different assumptions on this constant are cited, and it is shown in one particular example that the shearing stress on the cross section is not statically equivalent to the bending force. The definition of the shear center is critically reviewed, as well as some of its implications on recent investigations of turbine-blade vibration.

scholarly journals Analysis of the structure of liners used for the modernisation of brick collectors

2021 ◽  
Vol 43 (s1) ◽  
pp. 501-509
Author(s):  
Leszek Wysocki ◽  
Cezary Madryas ◽  
Jacek Grosel
Keyword(s):  
Cross Section ◽  
Flow Conditions ◽  
Pressure System ◽  
Optimal Flow ◽  
Pressure Line ◽  
Floor Slabs ◽  
The Cross ◽  
External Loads ◽  
Sewage Systems ◽  
Made In

Abstract Brick sewers were designed as egg-shaped, pear-shaped, bell-shaped, vaulted, and even rectangular (sometimes with granite ceilings and floor slabs). In exceptional cases, circular sections were also made of brick. Efforts were made in order to ensure optimal flow conditions, and also that the cross-section was adapted to the shape of the rock mass pressure line. This is due to the fact that the most advantageous shapes for masonry collectors are shapes in which no tensile stresses will occur in any part of the cross-section under the influence of external loads. Nevertheless, sewage conduits degrade over time. The boundary conditions of their use also change, which affects the magnitude of mechanical and hydraulic loads. Further use of a sewer in such a case requires its renewal, and less frequently, modernization that results from the necessity to change its function. This is usually done by introducing a new conduit into the interior of the renovated or modernized sewer, which in literature is called a liner. The aim of the analysis was to determine the thickness of the liners that strengthen the structures of brick channels with an inverted egg cross-section and with dimensions of 1050 × 700 mm, which are intended for gravitational sewage systems. The analysis included the performance of variant static and strength calculations for the assumption that the conduit after its modernization will be replaced with a conduit operating in the pressure system, which is a very rare requirement. It was assumed that the best solution would be to use a CIPP (Cured In Place Pipe) liner.

An Integrated Environment for Design and Analysis of Umbilical Cables

2017 ◽  
Author(s):  
Rodrigo Provasi ◽  
Leonardo Riccioppo Garcez ◽  
Christiano Odir Cardoso Meirelles ◽  
Clovis de Arruda Martins ◽  
Andre Freitas Barbosa ◽  
...  
Keyword(s):  
Cross Section ◽  
Environmental Conditions ◽  
Microsoft Word ◽  
Analytical Formulae ◽  
Cad Tool ◽  
The Cross ◽  
Definition Of ◽  
Umbilical Cable ◽  
Analytical Tools ◽  
Functional Components

The design of an umbilical cable begins with the definition of the operational functions it must implement and the environmental conditions to that it will be subjected to. Those functions suggest the components that it must have, usually chosen from a pre-defined set. Also, structural elements must be added, based on project and manufacture requirements, so the cable can withstand the environmental conditions of use. All the components must be geometrically arranged and the cross section of the cable must be defined, usually with the help of CAD software. But the structural behavior of the designed cable must be analyzed under several environmental conditions, using numerical and analytical tools. If this behavior does not fulfill the desired structural requirements, the cable must be redesigned: structural and functional components must be changed and the cross section of the umbilical must be rearranged in an iterative process. This article presents an environment that integrates a CAD tool dedicated to the design of the cross section of an umbilical cable with structural analysis tools, both analytical (Utilflex) and numerical (UFLEX2D). The CAD tool architecture is based on a component-instance model that enables both drawing and reusing of components. It also can export the designed cross-section to AutoCAD using AutoLISP language. Finally, it automates the generation of the data-sheet of the designed umbilical both in AutoLISP and Microsoft Word, including the basic structural properties calculated by means of analytical formulae.

THE RADAR CROSS SECTION OF A SEMI-INFINITE BODY

1960 ◽  
Vol 38 (1) ◽  
pp. 48-56 ◽  
Author(s):  
H. Brysk
Keyword(s):  
Plane Wave ◽  
Cross Section ◽  
Ad Hoc ◽  
Simultaneous Occurrence ◽  
Body Of Revolution ◽  
Infinite Body ◽  
Incident Plane ◽  
The Cross ◽  
The Difference ◽  
Definition Of

The concept of cross section as applied to a semi-infinite scattering body seems to require some clarification. The need for careful formulation of the problem arises because of the simultaneous occurrence of two characteristic lengths tending to infinity: the range from the radar to the target, and the size of the target. The infinite range assumption in the definition of the cross section allows the incident wave to be approximated as a plane wave in the case of a finite scatterer. For a semi-infinite body, it is customary to retain the plane-wave incidence, and introduce ad hoc arguments to dispose of the awkwardness due to the infinite extent of the scatterer. A return to the basic definition of a cross section, and examination of its motivation, lead here to an unequivocal formulation for the cross section of a semi-infinite body. Its consequences are pursued in the physical optics approximation. In particular, the nose-on backscattering from a body of revolution is exhibited, and results are computed for the paraboloid and the cone (which turn out to agree with the traditional ones). The broadside backscattering from a cylinder is also calculated, and the difference in this case between mono-static backscattering and the return in the backward direction from an incident plane wave is discussed.

Is the Stress Distribution Uniform in the Cross Section of SMA Bars Subjected to Uniaxial Loading? Is it Related to Rate Dependency?

2011 ◽  
Author(s):  
Reza Mirzaeifar ◽  
Reginald DesRoches ◽  
Arash Yavari
Keyword(s):  
Boundary Condition ◽  
Stress Distribution ◽  
Latent Heat ◽  
Cross Section ◽  
Cross Sections ◽  
Uniaxial Loading ◽  
Rate Dependency ◽  
The Cross ◽  
Definition Of ◽  
Vast Range

In this paper, a coupled thermo-mechanical framework which takes into account the effect of phase transformation latent heat is presented for shape memory alloys. The governing equations are discretized for SMA bars and wires with circular cross sections by considering the non-uniform temperature distribution in the cross section. It is shown that a combination of three various effects (boundary condition, loading rate, and size) governs the intensity of temperature gradient in the cross section of SMA bars subjected to uniaxial loading. Also, it is shown that because of the strong coupling between the thermal and mechanical fields in SMAs, temperature difference in the cross section causes a non-uniform stress distribution in the cross section. The maximum non-uniformity in the stress and temperature distributions are calculated for a vast range of practical sizes, boundary conditions, and loading rates. The relation between the latent heat flux in the cross section and the rate dependency is studied. It is shown that the rate dependency in the response of SMAs cannot be studied independent of size and boundary condition effects. This phenomenon reveals that the definition of quasi-static loading is not absolute; it is affected by a number of parameters, e.g., the ambient condition and size of the structure.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

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