Re, well now that the kids are at bedtime:
You will need to do at least two separate simulations with different remote ground locations (one at the extreme limit of the cantilever , in the center and at an angle as if the operator were leaning over the railing). It will also be necessary to do a simulation with 3 operators of 95 kg to get closer to the unusual but surely not so rare conditions of use. For this type of structure you need a resistance of 500 kg per m² (but you know that)
So with a distributed load of 250kg/m² we cover the case of a 90kg person on 0.36m² (600x600 square). As a general rule I define 250 for a technical gateway, more depending on the uses, and I have a nice "maximum load" plate engraved that I put on my gangways. For the 500, do you have a standard that imposes this? I go up as needed if motorized vehicles pass through
Another important point: you can also do your test without anchor bolts (even if bolt connectors are very useful to know the axial forces), just make a sketch of the size of the washers and make these eight areas fixed. This allows you to better see the deformation of the gantry footings.
But my goal is to get out of the effort to check the slab or size a bed. Impossible in this case I think?
On the other hand, your client should not make the classic mistake of taking the results of the simulation at face value. The anchoring in the ground depends on the quality of the concrete, the size of the reinforced mass and especially the standards given by the suppliers for the diameters and depth of the anchor studs?
Right. In fact, most of the time we have the design and installation of the equipment, so I do my purchases (steel, anchoring material, screws, everything from A to Z), I design, we manufacture, we have it validated by inspection bodies if necessary (lifting equipment for example) and we install. In our case, we will drill the slab to see the thickness of the latter, and if that is not enough, we will open to pour a mass of sufficient depth for the anchors that I would have defined. On the other hand, concrete is not our job so we subcontract this part, it's up to me to give the resulting efforts to the concrete worker so that it does its job. To do this, I give him as much information as possible, sometimes the moment at the base of my feet out of a beam simu if I want to do it quickly, sometimes in axial effort. Here for once I find my efforts ridiculous considering what the studs take ^^
I take care of what doesn't concern me: but are you sure of the dimensions of your HEA.
[HS On]
In addition, they seem very oversized for the load
[HS /Off]
No, don't hit the head
No worries, we're here to talk about that :-)
From experience, I oversize cantilevered structures to avoid the "spring" effect when the part is used in a vacuum. I already have a client who started jumping on a structure that started to vibrate, and I ended up having to reinforce, even if with calculation notes and misuse on his part. This for the time being, the statics do not inform it, and it is the only module we have. And then if I go down in hea size, I gain 5kg/m (from hea140 to hea120), or about 20 kilos, which represents almost nothing on the quote we are going to make to the customer. We work on the unitary project so the optimization we draw a line under it to reduce the study time but while building in a correct way because in the end the goal is to keep the customer.
There you have it! Thank you for your little video. I'm going to relaunch a static study with your hypotheses just to see tomorrow morning.
On the other hand, I noticed that the axial force in the studs increases with the decrease in the screw passage diameters. Let me explain: I have a Ø20 hole to put Ø16 anchor rods (as a general rule we drill at 18 but depending on the accessibility for the perfo I increase the diameter). So in my simu on my diameter 20 I enter a rod of 16, a nut of Ø30 for example, it gives me an axial force. This effort increases if I keep the same assumptions but lower the Ø of passage to 18. Have you ever had the case?
Moreover, concerning the preload of the stud, I always enter it at 0 (torque or axial tightening is equal). Is this the right method? Because if I enter the tightening torque in the end, the von stress scale put in the results explodes the ceiling on the support surface of the nut!
HS- we can't quote on this forum!-
