Calculation of IPE beam

[Rolf007]

Hello.

How can I calculate if my IPE 180 beam (upright profile as IPE beam) can withstand a point load in the middle of a 5000 mm long beam fixed at two points at each end?

Question, how much point load in kN can such a beam withstand?

 

[fremax]

Depends on which deflection one accepts?

Kind regards, fremax

 

[Rolf007]

Max 3mm

 

[scorp1on]

Hello.

How can I calculate if my IPE beam size 180 (”standing” profile similar to an IPE beam) can withstand a point load in the middle of a 5000 mm long beam fixed at two points at each end.

Question, how much can such a beam withstand in point load in kN?

The approach, simply described, is to first determine which cross-section class the beam's parts belong to. There are 4 different classes. After that, you need to check the moment capacity, shear capacity (considering shear buckling if applicable), and check deformation. The approach is different depending on the cross-section class.

I did a quick calculation, and the cross-section belongs to Cross-section Class 1, and I assumed steel quality S275 and simply supported between the ends. The maximum point force in the middle is limited by the moment capacity, making the maximum point load 36.52 kN, noting that the utilization level is 100% in this case, and a safety margin is advisable. For this point load, the corresponding deformation is approximately 35 mm.

 

[scorp1on]

Max 3mm

Saw your post now. For that deformation, a maximum of 3 kN corresponding to 300 kg applies.

 

[Rolf007]

Hello, thanks for that. I see that the load isn't much, so I have to rethink. I can confirm that the steel quality is S235.

If I need to handle 60kN distributed over two points, 1/3 in from each side, which IPE beam would that be?

Length 5000 mm and Max deflection 3 mm.

 

[Erik Lindroos]

Hi, thank you for that. I see that there isn't much load, so I need to reconsider. I can confirm that the steel quality is S235.

If I need to withstand 60kN distributed at two points, 1/3 in from each side, what IPE beam would that be?

Length 5000 mm and Max deflection 3 mm

According to my "beam app," you need some heavy-duty gear: IPE450. That results in a deflection of 3 mm. Good margin against the yield point as the maximum stress is around 45 MPa.

 

[Rolf007]

Thank you for that, this balk app is it something one can download to calculate themselves? Grateful for the forum's posts.

 

[Erik Lindroos]

Thank you for that, is this beam app something you can download to do your own calculations? Grateful for the forum posts.

There are several, search for "beam calculator". The one I have is called SkyCiv. Not very intuitive, but I have found it useful (haven't tried others).

 

[scorp1on]

According to my "beam app," substantial elements are required: IPE450. Then the deflection becomes 3 mm. Good margin against yield strength as the max stress will be around 45 MPa.
[image]

An IPE400 is sufficient, with deflection then being 2.6 mm.

 

[Erik Lindroos]

An IPE400 is sufficient, the deflection will then be 2.6 mm.

Hmm, interesting. Could it be differences in profile definition? I only used the built-in IPE-beam ("European standard") in the app. Can't see the moment of inertia explicitly. Which moment of inertia did you use? It could also differ in the modulus of elasticity, but that doesn't vary much between steel grades.

Addition: Must have made a mistake last time. Now I'm getting 3.0 mm deflection with IPE400 (including self-weight). 2.2 mm for IPE450. Still more than your 2.6 mm, but it seems that IPE400 is sufficient.

 

[scorp1on]

Thank you for that, is this beam app something one can download to calculate themselves? Grateful for the forum's posts.

An IPE400 is enough, if you want

Thank you for that, is this beam app something one can download to calculate themselves? Grateful for the forum's posts.

Hmm, interesting. Could there be differences in the profile definition? I only used the built-in IPE beam ("European standard") in the app. I can't see the moment of inertia explicitly. Which moment of inertia did you use? There could also be differences in the modulus of elasticity, but it doesn't vary much between steel grades.

Moment of inertia: 23130 x 10^4 mm4, sourced from Tibnor construction tables.
Modulus of elasticity: 210 GPa

It can also differ in the solution method as most apps do not use an analytical method but an approximate one via the finite element method.

 

[scorp1on]

Thanks for that, is this beam app something you can download to do the calculations yourself? Grateful for the forum's posts.

You can, for example, use an online one called https://clearcalcs.com/freetools/beam-analysis/au, but note that they use the finite element method. So it is not an exact solution but very close.

 

[Erik Lindroos]

An IPE400 is enough, do you wish



Moment of inertia: 23130 x 10^4 mm4, sourced from Tibnor construction tables.
Modulus of elasticity: 210 GPa

It can also differ in the solution method as most apps do not use an analytical method but an approximate one via the finite element method.

Yes, that's the downside with apps, you never really know what's under the hood. Better to take out the old textbook and formula collection

 

[scorp1on]

Yes, that's the downside of apps, you don't really know what's under the hood. Better to bring out the old textbook and formula collection

Exactly