So this is my first look into Simulations on objects, and by the simulations, I have tested this with the idea that a lightbar at 100kmh will take around roughly 150kg of wind drag or 1,500 newtons (I rounded to 10 for 1KG = 10N, I think it’s closer to 9.8 or something)
By all the simulations, all buckling will occur at points where mounting bolts will sit, and it will bow outwards, addition of a washer will greatly increase the strength on the outside and the lightbar frame itself will increase the strength on the inside.
All simulations were done as if the object is printed in ABS plastic, obviously other plastics will yield different results, such as PETG which is my preferred plastic, and is not accounted for in the simulation software.
This is designed to slot into the top track of a Rhino Vortex Roof Rack, I have zero affiliation with Rhino Rack, their products, or their subsidiaries and this is NOT A RHINO APPROVED PRODUCT, this was done for fun.
As such, taking design inspiration from Rhino, this is a NON COMMERCIAL and NON DERIVATIVE object, if necessary to account for your lightbar, go nuts, modify it that much for some quirk of what you have, but I do not want to see derivatives popping up on Thingiverse.
Once again, I will stress that this was designed FOR FUN and was intended to see the limitations and advantages of the system in Fusion 360, I will be printing this myself and fitting my own lightbar to it, but I take zero responsibility for anyone elses lightbars potentially breaking off and being damaged/lost, I simply cannot provide that kind of advice based on the incredible breadth of lightbars on the market, printers, settings for printers, and plastics available.
USE THIS AT YOUR OWN RISK!!!
We personally printed mine in PLA at 0.1mm layer heights and 250 degrees
Best printed with the largest faces lying against the print bed, this was taken into account in design, I would also randomise the Z-Seam to ensure that there isn’t an introduced weak point in the Z seam of the model.
Best results I have personally found for things like this are a high (but not silly) amount of 3D Honeycomb infill, but for all purposes, the structural tests are assuming that the model will be solid, so keep that in mind, the software cannot account for 3D printing.