What is shear force and bending moment?

Shear force

Shear force is the force acting on a substance in a direction perpendicular to the extension of the substance, acting in a direction to a planar cross-section of a body. Shear force is the summation of the effect of shear stress over a surface and often results in shear strain. Shear force is an internal force in any material which is usually caused by any external force acting perpendicular to the material, or a force that has a component acting tangent to the material. Shearing forces are unaligned forces pushing one part of a body in one direction, and another part of the body in the opposite direction. When the forces are aligned into each other, they are called compression forces.

Bending moment

A bending moment is a force normally measured in a force x length (e.g. kNm). Bending moments occur when a force is applied at a given distance away from a point of reference; causing a bending effect. In the most simple terms, a bending moment is basically a force that causes something to bend. If the object is not well-restrained the bending force will cause the object to rotate about a certain point.

Shear and bending moment diagrams 

Shear and bending moment diagrams are analytical tools used in conjunction with structural analysis to help perform structural design by determining the value of shear force and bending moment at a given point of a structural element such as a beam. These diagrams can be used to easily determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure. Another application of shear and moment diagrams is that the deflection of a beam can be easily determined using either the moment area method or the conjugate beam method.

• Related Articles

• What are the checklists for column design, beam design and shear wall design?

  Checklist for column design​ Check the Grade of concrete Grade of steel Check concrete cover as per IS and suitable for the site Check the arrangement of the rebar system in the pre-processor. Check for code IS 456:2000 Check if the proper load ...

• What is partial release of fixity of beams?

  The release is removing the capacity of a certain structural member to support forces like bending moment, torsion (more of torsion in the next posts) axial and shear forces. But most often release means release of the bending moment. Another ...

• What are Difference between the thin shell, thick shell, membrane element and Layered. Uses and applications. Why?

  Thin Shell Element  Inplane & Out of plane stiffness shall be calculated by the program by performing analysis.  Finite element meshing is compulsory for modeling such type of element Applications Normal RC Beam and slab structures. Irregular slabs, ...

• What is stiffness modifiers?

  Shell or area element has two types of stiffnesses i.e. in-plane stiffness refers to f11, f22 and f12 and out-of-plane stiffness refers to m11, m22 and m12. Refer to the below Figure which shows the direction of local axes and their corresponding ...

• What is the Meshing in Finite Element Method?

  A mesh is a network of line elements and interconnecting nodes used to model a structural system and numerically solve for its simulated behavior under applied loading. First, computational techniques create an analytical model by populating the ...