static analysis

[MarcoDap]

Hello everyone, I would like to have a comparison with someone who cuffs with fem calculations in solid works.
I am encountering difficulty in validating an analysis that treats a 4-arm anchor fabricated with a 4-inch sheet that must have a 400-piece swl.
lower the chosen configuration by setting a load of 600 te placed in the upper eyelet (considering a safety factor of 1.5) and using a fixed connection in one of the arms speculating the most critical situation, so that there is only one arm anchor.
As you can see on the right, the maximum yield limit is far from the permissible one.

It may be that it is incorrect in the analysis configuration or simply that the sheet considered does not support such load. (b. the analysis was also carried out with sheets of 6 and 8 inches).

Thank you in advance and good evening.

March of April.

 

[meccanicamg]

What do you mean? And swl?
unit of measurement is explained for ordinary mortals.
first calculates by hand the simplified beam to have an idea of tension.
if you get tension over the ribbing you have to do two things:
- Mesh finer to see if von moses remains constant. if it increases means that lamezh is to be refined but there will be a geometric singularity to be analyzed
- switch to an elasto non-linear plastic analysis
- all that trigger doesn't allow the anchor arm to flet, so resell the constraints
- to see the bending of the arm again you have to put the snap in the eyelet and instead the forces on the arm

I'd say there's a lot to work on. It's not a simple toy.

other thing that comes to my mind, if you have a multi-body part and there are areas resting on edge you will get that the bodies disjoin and get very exaggerated values.

just to compare, I would export the step and with freecad with the fem module of calculix I would compare the results.

solidworks is faster for fems but sometimes does not handle particular cases as it should.

 

[meccanicamg]

for many years the acronym s.w.l. was used in industry and construction. safe working load, (in some cases also n.w.l., normal working load) to identify the "port" of a device.
but we who are Italian and we talk as we eat, simply "ported".

In reality we have to apply a force in n or in kn....so you can no longer talk about scope but force applied.

You will be ton equivalent maybe....but I didn't find it written anywhere.

It seems that you have applied 6000kn which is to consider the maximum limit. the value is nominal force is projected 1.5 times less, i.e. 4000kn.

345mpa (because you use n/m2 that you don't understand what we are talking about).
somewhere you have a singularity on edge or fitting is 1219mpa... which means you have plastified the material.
linear static analysis is not valid.

 

[meccanicamg]

then you have to go bilinear or better true curve.

 

[meccanicamg]

You're not giving us great information, nor the step of the anchor, so let's go nose.
if the sheet thickness is 3in for simplicity are 100mm. then about the beam, where the force f=6000kn is applied to 300mm.It's a bit rough but let's pretend it can be calculated as a beam.
so the formulas are these:the flender moment is worth mf=f•l=6'000'000n•300mm=1'800'000nmm.
the rectangular section has a bending module that is worth wf=jx/ymax=[(b•h³)/12]/(h/2)=[(100*300³)/12]/(300/2)=1'500'000mm3
the tension at the base of the disaster is worth s=mf/wf=1200mpa.

as you see the tensions are very high, well above the yielding of 345mpa.

surely in the throat will be lower the tension because the center of the anchor is to 4 welded plates and there is greater inertia.

in short there is to change approach and always compare the fem with a hand calculation. you who have the model do it with your true measurements.

 

[meccanicamg]

Hello everyone, I would like to have a comparison with someone who cuffs with fem calculations in solid works.
I am encountering difficulty in validating an analysis that treats a 4-arm anchor fabricated with a 4-inch sheet that must have a 400-piece swl.
lower the chosen configuration by setting a load of 600 te placed in the upper eyelet (considering a safety factor of 1.5) and using a fixed connection in one of the arms speculating the most critical situation, so that there is only one arm anchor.
As you can see on the right, the maximum yield limit is far from the permissible one.

It may be that it is incorrect in the analysis configuration or simply that the sheet considered does not support such load. (b. the analysis was also carried out with sheets of 6 and 8 inches).

View attachment 71864Thank you in advance and good evening.

March of April.

I've seen now that you've set the fem analysis wrong. It is true that gravitational acceleration is downward but this subtracts strength to the study. above all acts incorrectly in the area under the ink.
first do the studio with only applied force, but as mentioned in the previous posts put in the hook and apply the force to the anchor arm.
then refine the thing if you get congruent data.

 

[MarcoDap]

Good afternoon, I ask vein for the words expressed but working in brazil I did not think to write compatibly to yes, however both swl and you are what she explained.
Meanwhile I thank immensely for the detailed answers and clarity in the explanations.
that I have come to mind and that despite the study can be corrected, probably the configuration and thickness of the anchor material is not enough to support this scope.
In any case, I will try to do as you suggested and give you a return as soon as possible.
Thanks again.

 

[MarcoDap]

However in response to the positioning of the force on the eyelet is because I put as an hypothesis the condition that the anchor is hooked on the bottom and therefore fixed accordingly what pushes upward would be the handle with chain attached to the eyelet.
Now I don't know if it was correct in this way, but that was the reason.
If you need more detailed information, I can tell you what and provide you in the best way to answer them.
Thanks again.