What is a Cantilever and Cantilever Beam? | Example of Cantilever Beam
What is Cantilever?
A cantilever can be defined as a projecting member or beam supported at only one end and carries a load at only one end or distributed along the unsupported portion. The upper half of the cantilever beam’s thickness is subjected to tensile stress, tending to elongate the fibers, the lower half to compressive stress, tending to crush them.
It is the rigid structural member/element projecting from a vertical supporting member, especially when the projection is excellent with the depth. The upper part of the structure is in tension and the lower part in compression.
A cantilever is a rigid structural member extending horizontally and is supported at only on one end. Generally, it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural members, a cantilever beam can be formed as a beam, plate, truss, or slab.
When the beam is subjected to a structural weight at its far, unsupported end, the member carries the load or weight to the support where it applies shear stress and a bending moment. It allows overhanging structures without additional support.
What is a cantilever beam?
Cantilever beam means if one end or one point of the beam element is supported, the endpoint or the endpoint continuing over the support and the endpoint is not held by any support; that is, such beams are called cantilever beams.
It is a horizontal beam with only one end resting on the support and the other end in space. The loads on such a beam create tensile stress on the upper side and compressive stresses on the lower side. Cantilever beams are widely used in both buildings and machinery.
Any beam that comes out of a wall in the building and whose end is free is considered a cantilever beam. These carry structural elements such as roofs, eaves, and galleries, which are desired to be free.
Example of Cantilever Beam
Real-life applications of cantilever beams can be exemplified by stadiums, porches, gas station canopies (roof-type low-slope structure that covers the areas where the pumps are located at gas stations). Cantilever beams are also used in bridges where large spans and heavy loads are involved.
Cantilever beams are permitted under minimal conditions in reinforced concrete structures, but these limits can be exceeded much more in steel structures than reinforced concrete. For example, cantilever beams reaching 2 meters in reinforced concrete structures are rare but cantilevers up to 5 meters in steel structures and 10 meters according to the application can be made.
The most typical example of this is Forth Bridge in Scotland. Three gigantic pillars were used in the bridge, each consisting of two cantilever beams. There are also cranes operating on the cantilever beam principle installed to serve large areas such as construction sites or shipyards.
The relatively light ones of these are located on a mobile tower. The heavier loads are attached to a fixed building. A rotating pivot that descends to the ground causes the crane to rotate around itself.
Examples of Cantilever Beam Design
Conclusion on Cantilever Beam
Cantilever beams are often advantageous to use when the continuity condition is met. Especially if cantilever beams coming out of a person supported from two points have the ideal length, they will decrease the maximum moment value of the main beam and its moment; the value will give reasonable results.
While making cantilever beam calculations, attention should be paid to the length value, and very long cantilever designs should not be made unless necessary. Of course, as in every situation, long consoles have a solution with the right calculation.