Guide to how to design a beam which is required support a point load from another beam

If you need to design a steel beam which is going to support another steel beam, you will need to follow the following guidance.

First of all you will need to design the beam that is to be supported and then generate the pdf report, from the report you will then be able to get the factored beam end reaction. Click here to see an example showing where to locate the beam end reaction on the report.

The beam end reaction value includes variable and permanent safety factors which are 1.5 and 1.35 (see section 3 on the steel beam calculator), so to ensure you are not doubling up on the safety factors, the factored beam end reaction needs to be divided by the safety factor.

So when you enter the point load into the calculator, what you should do is take the factored beam end reaction, which is say 18.74kN on this pdf example, (your value will be different) and divide it by permanent load safety factor 1.35, so for example 18.74kN/1.35=13.88kN, you then need to enter the value of 13.88kN (yours will be different) into the permanent load and then enter the variable load as 0 (zero kN). In reality a proportion of the load may be variable (such as people, furniture etc.) and a proportion of the load is permanent (such as self weight of the floor, steel beam etc.) but for ease of calculation you can just assume all of the load is permanent load.

If the beam that is being supported is fixed/bolted to the other beam, this will provide a point of restraint along the length of the beam which is supporting the other beam, so say for example the beam is 3m long, but is supporting another beam that 2m from the end of the beam, the length between lateral restraints will be 2m as opposed to the beam length which is 3m, in theory this helps the supporting beam as it cannot fail in lateral torsional buckling at the point at where it is connected.

Also you may need to adjust the deflection limits (how much you allow the beam to sag) as you have assumed all of the point load is permanent load, you should consider changing the 'Total variable and permanent load deflection limit' to span/300 or span/360.

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