Beam Moment Support: Debunking the Need for End Moments

[chandran]

i have a beam with no constraints. Now i apply a moment at some point in the beam. Now am i correct to say that i need not fix the end of the beam(like a beam inserted into a wall). instead i could support the end of the beam like a simply supported beam.

because a moment tries to rotate the object with the axis as the point of application of moment. I can always prevent rotation by applying force at some other point(simulating like a simply supported beam).


This disproves the theory that the moment applied at some point of the beam should be supported by a moment at the end of the beam. Instead the beam can be supported by a force at the end of the beam

 

[Pyrrhus]

This disproves the theory that the moment applied at some point of the beam should be supported by a moment at the end of the beam. Instead the beam can be supported by a force at the end of the beam

What theory is this?

If you only support the beam by one end, and the support is not embedded (inserted in a wall), then your system is not stable. More equations than unknowns.

 

[charng]

.

I would like to clarify that the concept of moment support is not necessarily debunked in this scenario. While it is true that a moment applied at some point in the beam can be counteracted by a force at the end of the beam, this does not mean that moment support is not needed.

Moment support refers to the ability of a structure to resist moments, or rotational forces, that are applied to it. In the case of a beam with no constraints, the moment applied at some point will cause the beam to rotate around that point, unless there is a counteracting moment or force at the end of the beam. This is why traditional beam designs often include fixed or pinned supports at the ends, to resist these moments and prevent rotation.

In the scenario described, the end of the beam is being supported by a force, which is essentially acting as a moment in the opposite direction. This is still a form of moment support, as it is preventing the beam from rotating due to the applied moment. However, it is important to note that this type of support may not be sufficient in all cases and may not provide the same level of stability as traditional moment supports.

In conclusion, while it is possible to support a beam with an applied moment using a force at the end, this does not negate the need for moment support in structural design. The type and amount of support required will depend on various factors, such as the magnitude and location of the applied moment, the properties of the beam, and the intended use of the structure. it is important to carefully consider all of these factors in order to design safe and stable structures.