sf & bm diagram

7/28/2019 SF & BM Diagram

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Shear stress and

Bending momentDiagram

HarishGarg


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Shear stress

Shear stress is a stress state wherethe stress is parallel or tangential toa face of the material, as opposed tonormal stress when the stress is

perpendicular to the face. Thevariable used to denote shear stressis (tau).
http://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Parallelhttp://en.wikipedia.org/wiki/Tangent_%28geometry%29http://en.wikipedia.org/wiki/Normal_stresshttp://en.wikipedia.org/wiki/Perpendicularhttp://en.wikipedia.org/wiki/Tauhttp://en.wikipedia.org/wiki/Tauhttp://en.wikipedia.org/wiki/Perpendicularhttp://en.wikipedia.org/wiki/Normal_stresshttp://en.wikipedia.org/wiki/Tangent_%28geometry%29http://en.wikipedia.org/wiki/Parallelhttp://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Stress_%28physics%29


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Bending moment

A bending moment exists in a structuralelement when a moment is applied to theelement so that the element bends.

Moments and torques are measured as aforce multiplied by a distance so theyhave as unit newton-metres (Nm) , orfoot-pounds force . The concept of

bending moment is very important inengineering and physics.
http://en.wikipedia.org/wiki/Moment_%28physics%29http://en.wikipedia.org/wiki/Newton-metrehttp://en.wikipedia.org/wiki/Foot-pounds_forcehttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Physicshttp://en.wikipedia.org/wiki/Physicshttp://en.wikipedia.org/wiki/Engineeringhttp://en.wikipedia.org/wiki/Foot-pounds_forcehttp://en.wikipedia.org/wiki/Foot-pounds_forcehttp://en.wikipedia.org/wiki/Foot-pounds_forcehttp://en.wikipedia.org/wiki/Newton-metrehttp://en.wikipedia.org/wiki/Newton-metrehttp://en.wikipedia.org/wiki/Newton-metrehttp://en.wikipedia.org/wiki/Moment_%28physics%29


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Convention

Although these conventions are relative and any convention can beused if stated explicitly, practicing engineers have adopted a standard

convention used in design practices.The normal convention used in most engineering applications is to label a

positive shear force one that spins an element clockwise (up on the left, anddown on the right). Likewise the normal convention for a positive bending

moment is to warp the element in a "u" shape manner (Clockwise on the left,

and counterclockwise on the right).

This convention was selected to simplify the analysis of beams. Since a horizontal

member is usually analyzed from left to right and positive in the vertical direction is

normally taken to be up, the positive shear convention was chosen to be up from the left,

and to make all drawings consistent down from the right. The positive bending convention

was chosen such that a positive shear force would tend to create a positive moment.
http://upload.wikimedia.org/wikipedia/en/d/d2/Shear_and_Moment_Convention.jpg


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Structural loads

Structural loads are forces applied to a component ofa structure or to the structure as a unit.

In structural design, assumed loads are specified innati

onal and local design codes for types of structures,

geographic locations, and usage. In addition to the loadmagnitude, its frequency of occurrence, distribution,and nature (static or dynamic) are important factors indesign. Loads cause stresses, deformations anddisplacements in structures. Assessment of theireffects is carried out by the methods ofstructuralanalysis. Excess load or overloading may causestructural failure, and hence such possibility should beeither considered in the design or strictly controlled.
http://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Structural_designhttp://en.wikipedia.org/wiki/Design_codehttp://en.wikipedia.org/wiki/Design_codehttp://en.wikipedia.org/wiki/Design_codehttp://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Deformationhttp://en.wikipedia.org/wiki/Displacement_%28vector%29http://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Deformationhttp://en.wikipedia.org/wiki/Displacement_%28vector%29http://en.wikipedia.org/wiki/Structural_analysishttp://en.wikipedia.org/wiki/Structural_analysishttp://en.wikipedia.org/wiki/Structural_analysishttp://en.wikipedia.org/wiki/Structural_failurehttp://en.wikipedia.org/wiki/Structural_failurehttp://en.wikipedia.org/wiki/Structural_failurehttp://en.wikipedia.org/wiki/Structural_failurehttp://en.wikipedia.org/wiki/Structural_analysishttp://en.wikipedia.org/wiki/Structural_analysishttp://en.wikipedia.org/wiki/Displacement_%28vector%29http://en.wikipedia.org/wiki/Deformationhttp://en.wikipedia.org/wiki/Stress_%28physics%29http://en.wikipedia.org/wiki/Design_codehttp://en.wikipedia.org/wiki/Structural_designhttp://en.wikipedia.org/wiki/Force


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Structural loads

Dead loadsDead loads are weights of material, equipment orcomponents that are relatively constant throughout thestructure's life. Permanent loads are a wider categorywhich includes dead loads but also includes forces set

up by irreversible changes in a structure's constraints -for example, loads due to settlement, the secondaryeffects ofprestress or due to shrinkage and creep inconcrete. Dr. Nyassi recomments this effort

Live loads

Live loads are temporary, ofshort duration, or moving.Examples include snow, wind, earthquake, traffic,movements, water pressures in tanks, and occupancyloads. For certain specialized structures, vibro-acousticloads may be considered.
http://en.wikipedia.org/wiki/Settlement_%28construction%29http://en.wikipedia.org/wiki/Prestressed_concretehttp://en.wikipedia.org/wiki/Settlement_%28construction%29http://en.wikipedia.org/wiki/Creep_%28deformation%29http://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Prestressed_concretehttp://en.wikipedia.org/wiki/Creep_%28deformation%29http://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Snowhttp://en.wikipedia.org/wiki/Windhttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Traffichttp://en.wikipedia.org/wiki/Motion_%28physics%29http://en.wikipedia.org/wiki/Snowhttp://en.wikipedia.org/wiki/Windhttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Traffichttp://en.wikipedia.org/wiki/Motion_%28physics%29http://en.wikipedia.org/wiki/Motion_%28physics%29http://en.wikipedia.org/wiki/Traffichttp://en.wikipedia.org/wiki/Earthquakehttp://en.wikipedia.org/wiki/Windhttp://en.wikipedia.org/wiki/Snowhttp://en.wikipedia.org/wiki/Concretehttp://en.wikipedia.org/wiki/Creep_%28deformation%29http://en.wikipedia.org/wiki/Prestressed_concretehttp://en.wikipedia.org/wiki/Settlement_%28construction%29


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Beam (structure)

A beam is a structural element that is capable ofwithstanding load primarily by resisting bending. Thebending force induced into the material of the beam asa result of the external loads, own weight and external

reactions to these loads is called a bending moment.
http://en.wikipedia.org/wiki/List_of_structural_elementshttp://en.wikipedia.org/wiki/Structural_loadhttp://en.wikipedia.org/wiki/Bendinghttp://en.wikipedia.org/wiki/Bending_momenthttp://en.wikipedia.org/wiki/Bending_momenthttp://en.wikipedia.org/wiki/Bendinghttp://en.wikipedia.org/wiki/Structural_loadhttp://en.wikipedia.org/wiki/List_of_structural_elements


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Shear Forces & Bending Moments I

Simply supported beam


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Shear Forces and Bending Moments

The Shear Force is positive if it tends to rotate the beam sectionclockwise with respect to a point inside the beam section.

The Bending Moment is positive if it tends to bend the beam sectionconcave facing upward. (Or if it tends to put the top of the beam intocompression and the bottom of the beam into tension.)


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Simply Supported Beam

Simply supported beam


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Superposition


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Cantilever with End Load


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Cantilever with Intermediate Load


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Cantilever with Uniform Load


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Cantilever with Moment Load


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Simple Supports with IntermediateLoad


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Simple supports with Uniform Load


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Simple Supports with Moment Load


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Simple Supports with Overhanging

Load


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Cantilever with Partial Distributed Load


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Simple Supports with Partial Distributed

Load


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sf & bm diagram

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