The shear force diagram, which is also known as S.F.D, is a diagram used for representing the disparity of shear force laterally on a beam. In solid mechanics books, shearing forces are the unaligned (not arranged in a straight line, in parallel) forces that push one part of a body in a particular direction and another part of the body in the opposite direction.
In other words, a force acting in a specific direction parallel to a surface or a planar cross-section of a body. Let us take one example to make you understand better. A deck of cards is being pushed one way on the top and the other at the bottom, causing cards to slide.
A shear force diagram can quickly determine the type, size, and material of a member in a structure. It will help in supporting a given set of loads without structural failure. The most common domain where the term shear force is used is in the context of architecture and construction. Shear forces are a critical consideration in construction. If they are not calculated correctly, the structure might be unstable.
Why is shear force important?
Shear forces are one of the most fundamental and common physical forces you’ll encounter daily. For example, you apply shear force whenever you cut fruit or bend your body. Likewise, they are an essential factor while building design and engineering.
For example, a shear force can help you to estimate how much weight a beam (one that holds up a roof or floor) can hold before it bends or breaks.
Purpose of Shear Force Moment Diagram
- The shear force diagram can be used to analyze the beam.
- Through this diagram, we can estimate the shear force resisted by the beam section along the length of the beam.
- Shear force diagrams are used as analytical tools. It is used parallelly with structural analysis, which then helps perform structural design by determining the value of shear force at a given point of an element.
- The type and size of a member of a given material can be easily determined with the help of a shear diagram.
- Deflection can be easily determined with the help of a shear diagram.
Important points to be kept in mind while drawing the shear force diagram
- Firstly, choose either the right-hand side or the left-hand side of the section.
- Now, add the regular forces to the beam on one of the sides. If you choose the right-hand side of the section, the force acting downwards is taken +ve, whereas the force working upwards is -ve.
- The +ve values of a shear force are plotted above the baseline and -ve values below the baseline.
- The shear force diagram will either increase or decrease suddenly by a vertical straight line at a section with a vertical point load.
- The shear force between any two vertical loads will be constant; hence, the shear force diagram between two vertical loads will be horizontal.
Conclusion
A shear force diagram views the shear force at every section of the beam because of its transverse loading. The shear force diagram is handy in architecture and building design. They help in ensuring the safety and security of a building. In this article, you will find all about the shear force diagram and the points to keep in mind while making a shear force diagram.
