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A beam is a structural element that carries load primarily in bending (flexure). Beams generally carry vertical gravitational forces but can also be used to carry horizontal loads (i.e. loads due to an earthquake). The loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members. In Light frame construction the joists rest on the beam. Image File history File links A simply supported beam before and after the application of a uniform lateral load. ...
In statics, a construction is statically indeterminate when the static equilibrium equations are not sufficient to calculate the reactions on that construction. ...
The structure of a thing is how the parts of it relate to each other, how it is put together. This contrast with process, which is how the thing works; but process requires a viable structure. ...
This article or section does not cite its references or sources. ...
Figure 1. ...
An object is in a vertical position when it is aligned in an up-down direction, perpendicular to the horizon. ...
This article covers the physics of gravitation. ...
In physics, force is an influence that may cause a body to accelerate. ...
Horizontal is an orientation relating to, or in parallel with the horizon, and thus perpendicular to the vertical. ...
An earthquake is a phenomenon that results from the sudden release of stored energy in the Earths crust that creates seismic waves. ...
Deconstructing a Roman pillar. ...
WALL is a radio station licenced to Middletown, New York that serves Orange County, New York. ...
This page is a candidate to be copied to Wiktionary. ...
Columns Ionic column base A compression member is a general class of structural elements of which a column is the most common specific example. ...
It has been suggested that this article or section be merged into Platform framing. ...
A joist, in architecture and engineering, is one of the horizontal supporting members that run from wall to wall, wall to beam or beam to beam, to support a ceiling, roof (or floor). ...
Beams are characterized by their profile (the shape of their cross-section), their length, and their material. In contemporary construction, beams are typically made of steel, reinforced concrete, or wood. One of the most common types of steel beam is the I-beam or wide-flange beam (also known as a "universal beam" or, for stouter sections, a "universal column"). This is commonly used in steel-frame buildings and bridges. Other common beam profiles are the C-channel, the hollow structural section beam, the pipe, and the angle. Look up material in Wiktionary, the free dictionary. ...
In large construction projects, such as skyscrapers, cranes are essential. ...
The old steel cable of a colliery winding tower Steel is an alloy whose major component is iron, with carbon content between 0. ...
Reinforced concrete at Sainte Jeanne dArc Church (Nice, France): architect Jacques Dror, 1926–1933 Reinforced concrete, also called ferroconcrete in some countries, is concrete in which reinforcement bars (rebars) or fibers have been incorporated to strengthen the material that would otherwise be brittle. ...
Trunks A tree trunk as found at the Veluwe, The Netherlands Wood is a solid material derived from woody plants, notably trees but also shrubs. ...
I-beams are beams with an I- or H-shaped cross-section. ...
Look up flange in Wiktionary, the free dictionary. ...
This article is about the edifice (including an index to articles on specific bridge types). ...
Structural steel is steel construction material, a profile, formed with a specific shape and certain standards of chemical composition and strength. ...
Hollow structural section (HSS) is a type of beam with a hollow rectangular cross-section. ...
Pipe is a tube or hollow cylinder for the conveyance of fluid. ...
Structural steel is steel construction material, a profile, formed with a specific shape and certain standards of chemical composition and strength. ...
Structural Characteristics Internally, beams experience compressive, tensile and shear stresses as a result of the loads applied to them. Typically, under gravity loads, the original length of the beam is slightly reduced to enclose a smaller radius arc at the top of the beam, resulting in compression, while the same original beam length at the bottom of the beam is slightly stretched to enclose a larger radius arc, and so is under tension. The same original length of the middle of the beam, generally halfway between the top and bottom, is the same as the radial arc of bending, and so it is under neither compression nor tension, and defines the neutral axis (dotted line in the beam figure). Above the supports, the beam is exposed to shear stress. There are some reinforced concrete beams that are entirely in compression. These beams are known as prestressed concrete beams, and are fabricated to produce a compression more than the expected tension under loading conditions. High strength steel tendons are stretched while the beam is cast over them. Then, when the concrete has begun to cure, the tendons are released and the beam is immediately under eccentric axial loads. This eccentric loading creates an internal moment, and, in turn, increases the moment carrying capacity of the beam. They are commonly used on highway bridges. Physical compression is the result of the subjection of a material to compressive stress, resulting in reduction of volume. ...
Tension is a reaction force applied by a stretched string (rope or a similar object) on the objects which stretch it. ...
In physics and mechanics, shear refers to a deformation that causes parallel surfaces to slide past one another (as opposed to compression and tension, which cause parallel surfaces to move towards or away from one another). ...
Stress is the internal distribution of force per unit area that balances and reacts to external loads applied to a body. ...
Shear stress is a stress state where the stress is parallel to a face of the material, as opposed to normal stress when the stress is perpendicular to the face. ...
Concrete is strong in compression but weak and structurally unreliable in tension. ...
The primary tool for structural analysis of beams is the Euler-Bernoulli beam equation. Other mathematical methods for determining the deflection of beams include "method of virtual work" and the "slope deflection method". Engineers are interested in determining deflections because the beam may be in direct contact with a brittle material such as glass. Beam deflections are also minimised for aesthetic reasons. A visibly sagging beam, though structurally safe, is unsightly and to be avoided. A stiffer beam (high modulus of elasticity and high second moment of area produces less deflection. Mathematical methods for determining the beam forces (internal forces of the beam and the forces that are imposed on the beam support) include the "moment distribution method", the force or flexibility method and the matrix stiffness method. The elementary Euler-Bernoulli beam theory is a simplification of the linear isotropic theory of elasticity which allows quick calculation of the load-carrying capacity and deflection of common structural elements called beams. ...
[[ Deflection happens when an object hits a plane surface In physics In physics deflection is the event where an object collides and bounces against a plane surface. ...
A force F, which may be real (actual) or imaginary (fictitious), acting on a particle is said to do virtual work when the particle is imagined to undergo a real or imaginary displacement component D in the direction of the force. ...
A material is brittle if it is subject to fracture when subjected to stress i. ...
Stiffness is the resistance of an elastic body to deflection by an applied force. ...
In solid mechanics, Youngs modulus (also known as the modulus of elasticity or elastic modulus) is a measure of the Stiffness of a given material. ...
The second moment of area, also known as the second moment of inertia and the area moment of inertia, is a property of a shape that is used to predict its resistance to bending and deflection. ...
Hardy Cross, 1885-1959, born in Nansemond County, Virginia. ...
In structural engineering, the flexibility method is the classical consistent deformation method for computing member forces and displacements in structural systems. ...
In structural engineering, the matrix stiffness method (or simply stiffness method) is a matrix method that makes use of the members stiffness relations for computing member forces and displacements in structures. ...
General Shapes
 Diagram of stiffness of a simple square beam (A) and I-beam (B). The I-beam flange sections are three times further apart than the solid beam's upper and lower halves. The second moment of inertia of the I-beam is nine times that of the square beam of equal cross section (I-beam web ignored for simplification) Mostly the beams have rectangular cross sections in reinforced concrete buildings, but the most efficient cross-section is an I-shaped beam. The fact that most of the material is placed away from the neutral axis (axis of symmetry in case of I beams) increases the second moment of area of the beam which in turn increases the stiffness. Image File history File links Download high-resolution version (924x713, 28 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Beam (structure) ...
Image File history File links Download high-resolution version (924x713, 28 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Beam (structure) ...
Reinforced concrete at Sainte Jeanne dArc Church (Nice, France): architect Jacques Dror, 1926–1933 Reinforced concrete, also called ferroconcrete in some countries, is concrete in which reinforcement bars (rebars) or fibers have been incorporated to strengthen the material that would otherwise be brittle. ...
An axis in the cross section of a beam, shaft or the like along which there are no longitudinal stresses / strains. ...
The second moment of area, also known as the second moment of inertia and the area moment of inertia, is a property of a shape that is used to predict its resistance to bending and deflection. ...
An I-beam is only the most efficient shape in one direction of bending: up and down looking at the profile as an I. If the beam is bent side to side , it functions as an H and is less efficient. The most efficient shape for both directions in 2D is a box (a square shell) however the most efficient shape for bending in any direction is a cylindrical shell or tube. But, for unidirectional bending, the I beam rules.
Efficiency means that for the same cross sectional area (Volume of beam per length) subjected to the same loading conditions, the beam deflects less.
Other shapes, like L (angles), C (Channels) or tubes, are also used in construction when there are special requirements.
See also Figure 1. ...
A bending moment in physics is an example of an internal force that is induced in a structure when loads are applied to that structure. ...
This article is about the edifice (including an index to articles on specific bridge types). ...
A building code is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings and nonbuilding structures. ...
Classical mechanics is a branch of physics which studies the deterministic motion of objects. ...
Columns Ionic column base A compression member is a general class of structural elements of which a column is the most common specific example. ...
[[ Deflection happens when an object hits a plane surface In physics In physics deflection is the event where an object collides and bounces against a plane surface. ...
Elasticity is a branch of physics which studies the properties of elastic materials. ...
For other uses, see Plasticity. ...
To meet Wikipedias quality standards, this article may require cleanup. ...
I-beams are beams with an I- or H-shaped cross-section. ...
A joist, in architecture and engineering, is one of the supporting bars that run from wall to wall to support a ceiling (or floor). ...
It has been suggested that Stick-frame construction be merged into this article or section. ...
The Materials Science Tetrahedron, which often also includes Characterization at the center Materials science is an interdisciplinary field involving the properties of matter and its applications to various areas of science and engineering. ...
It has been suggested that Tensile strength be merged into this article or section. ...
In physics, the moment of force (often just moment, though there are other quantities of that name such as moment of inertia) is a quantity that represents the magnitude of force applied to a rotational system at a distance from the axis of rotation. ...
An elastic modulus, or modulus of elasticity, is the mathematical description of an object or substances tendency to be deformed when a force is applied to it. ...
Finite element method (FEM) is a powerful technique originally developed for numerical solution of complex problems in structural mechanics, and it remains the method of choice for complex systems. ...
Figure 1: Rectangular specimen subject to compression, with Poissons ratio circa 0. ...
The second moment of area, also known as the second moment of inertia and the area moment of inertia, is a property of a shape that is used to predict its resistance to bending and deflection. ...
(UTC)Shear strength in geology and geotechnical engineering is a term used to describe the strength of soils, to resist deformation due to shear stress. ...
Shear stress is a stress state where the stress is parallel to a face of the material, as opposed to normal stress when the stress is perpendicular to the face. ...
Span is a section between two intermediate supports of a bridge. ...
Statics is the branch of physics concerned with physical systems in static equilibrium, that is, in a state where the relative positions of subsystems do not vary over time, or where components and structures are at rest under the action of external forces of equilibrium. ...
In statics, a construction is statically indeterminate when the static equilibrium equations are not sufficient to calculate the reactions on that construction. ...
Stress is the internal distribution of force per unit area that balances and reacts to external loads applied to a body. ...
This article is about the deformation of materials. ...
Structural analysis comprises the set of physical laws and mathematics required to study and predict the behavior of structures. ...
This article or section does not cite its references or sources. ...
Tensile strength measures the force required to pull something such as rope, wire, or a structural beam to the point where it breaks. ...
Tensile stress (or tension) is the stress state leading to expansion; that is, the length of a material tends to increase in the tensile direction. ...
Hookes law accurately models the physical properties of common mechanical springs at small extensions. ...
The worlds first double curvature lattice steel Shell by V.G.Shukhov (during construction), Vyksa near Nizhny Novgorod, 1897 Thin-shell structures can be defined as curved structures capable of transmitting loads in more than two directions to supports. ...
Truss bridge for a single track railway, converted to pedestrian use and pipeline support. ...
Yield strength, or the yield point, is defined in engineering and materials science as the stress at which a material begins to plastically deform. ...
External Links
References - Introduction to mechanics of solids, Egor P. Popov, Prentice-Hall, 1968
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