Questions tagged [beam]

Questions about the theory and applications of structural elements designed to resist bending.

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Is the Qmax of an T-Beam equal if calculated both above and below the neutral plane?

I was doing a question involving a T-Beam question wrong since I was selecting the wrong area to use for $Q_{max}$ when trying to maximise the shear stress. $$\large{\tau}= \frac{VQ}{It}$$ A friend ...
3
votes
1answer
3k views

Effective length for lateral torsional buckling in a laced strut

When loaded vertically, a beam experiences compression in its top flange and tension in its bottom flange. The top (compression) flange would tend to buckle vertically much like a column, however, the ...
12
votes
1answer
4k views

At what point does an I-beam becomes a H-beam?

According to BS5950, a beam section can be classified as plastic, semi-compact, compact or slender. For the same section area, a H-beam can take axial compression (without buckling) better than an I-...
10
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3answers
5k views

Why is it unwise to choose cylindrical horizontal beam

I heard that it is unwise to choose cylindrical horizontal beam. My question is why?
11
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4answers
4k views

How do I calculate the forces on a desk and its legs?

I have a design for a desk, and I'd like to not just guess at how strong it'll be, but I can't find an explanation on how to figure out all the forces involved that doesn't assume I already know a lot ...
12
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4answers
966 views

Easy nonlinear model for large deformation of a beam

I have a beam subject to twisting and/or bending forces as well as linear compression force along its main axis. It is modelled as an isotropic beam, but if anisotropic is not too far off then that's ...
5
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4answers
7k views

How do you calculate Mcr (critical buckling moment)

When designing a steel beam, the resistance to buckling is related to Mcr; the elastic critical moment for lateral-torsional buckling. However the Eurocodes give no advice about how to calculate this ...