Hello
I modeled a spaghetti bridge on SolidWorks using mechanically welded elements. I have arranged the fixed geometries at the four ends and the load at the two middle connections is evenly distributed. My problem is when I mesh and run, the two tubes at the ends at the top are not taken into account in the simulation!
Here are some pictures if you have an idea like that. And if you need the model tell me I'll make you a pack and go...
Thank you for your help!
Hello 972arthur972,
For me, when I see your model, I find that there are the two top irons that touch or intersect. You have to check an option that indicates without penetration.
Well, I had this training not long ago, but I'm going to find you what you're looking for.
… @+.
AR.
Hello
We should look first at the level of the model itself (outside the simu tab)
So I'd say that you have beams that don't intersect if I read the first image correctly.
And this on the two verticals of the center and obviously those that form the arches (vault)
If you were in volume you would have had a message about collisions during the mesh.
Even spaghetti doesn't interpenetrate 
[HS On]
If I can afford that it's a spaghetti bridge or a real bridge, you can't have a succession of straight lines (like a panel) to make the two curves that serve as reinforcement.
{HS /Off]
Kind regards
PS: You can post your asm with a pack and go if you want
Here are two photos a little closer:
I purposely made four arches one by one using the removal of material thanks to the tool extruded by a profile each time so that they don't cross each other...
But as you can see, there is a " hole " at the top of the arch, I can't put a mouthpiece, I don't really see how to make an apartment, cut shorter with my removal of material and make a cover afterwards but I'm not very comfortable with this tool!
Thanks again for helping me!
First of all, thank you for your answer! Regarding the arches partitioned into segments, it was a basic sketch to allow us to do it in real life and I relied on it to find out how much the bridge could have held in the ideal world where it would have been symmetrical.
Good evening
It's normal that it doesn't work well because your parts are in beam mode.
However, this mode does not support beveled parts well. The beams do not have to be machined.
A bit long to explain to you!
The most effective way is to switch all your parts to volume mode.
On the other hand, as the summit join is not total (you have a void) you will have a weak point that will be very visible in the simulation.
Be careful to have one side of the bridge in fixed support on an edge and on the other side to have a flat support to allow horizontal movement. (no total cantilever).
Kind regards
PS: personally I wouldn't have made a bevel on the tubes, it will weaken this area a lot and it's up to you to see if aesthetics are worth the candle
If you have any difficulties, post with a pack and go
Thank you for your help.
Good night
Hello
If I don't say too much nonsense, generally the purpose of these calculations is to check the constraints at the nodes and possibly in the bars?
So my opinion is that there's no point in adjusting the bevel cuts because it interferes with the results.
Try to stay in calculation in beam mode but simply do your mechanically welded profile operation in 2 steps so as not to have any adjustment in the upper part.
Hello @972arthur972 ,
How about modeling using the basic volume functions of SolidWorks? Essentially volumes by smoothing circular sections, using the same 3D sketch as that used in the design with the " Welded Constructions " module.
And by checking the merge volumes box, which has the effect of eliminating any problems with the adjustment of the members or the bevel fitting...
The simulation does not present any difficulty, provided that it is admitted that the connections between members are embedded. What else?
And to reserve the " welded construction" in case a manufacturing file needs to be produced, with drawings, bills of materials and other documents.
I don't think that's a goal for a spaghetti bridge...
Hello, I followed your advice and made the same structure with sweeps by merging everything each time. However, when I mesh my volume model, I get an error no matter how fine the mesh is... Do you know where this can come from? I added an iron axle to the center to be able to put the force on it. Even this one, the mesh is not done, it's the first time I've used this simulation tool, I don't know all of them, far from it.
Thank you very much for your help!
Hello
The standard meshinger used by default in SolidWorks is often undermined when the geometry becomes complex. This is probably the central area where the rays converge.
The " curvature-based" and " connected" algorithms are used to improve the quality of the ... " are much more effective, in particular by refining the mesh in the tortured areas.
It is also possible to fine-tune the general mesh using the " Mesh density" slider.
Attached, the model I made (SW 2021).
Kind regards
SpaghettiV2021.SLDPRT (1.4 MB)
