I have just designed a trailer axle, this axle is made from a round steel tube of Ø78mm outside, and Ø70mm inside. For the strength tests, I removed the hubs and wheels, and I placed the axle on two steel blocks that serve as supports (see attached drawing).
When I apply a total load of 10N to the 2 upper supports, they bend as if I had exerted a load of several tens of tons, or as if the tube were made of foam. Worse, under its own weight, (see gravity test in attached image), the axle bent. However, I have assigned the right material to all the parts, alloy steel, I have tried all the metals, and I have the same result.
I also tried to follow this tutorial to the letter: https://www.youtube.com/watch?v=bNvGjFtHPdc
And also this one: https://www.youtube.com/watch?v=sfuHPrtcZ0g
Another example with a 50mm and 3mm thick square tube section. I applied a weight of 10g, and then a weight of 100Kg. We can see that the results are strictly identical. Whereas such a tube, even with 100Kg, should not move. Even if I put the weight of a feather, I would have the same result.
Indeed, it is better to be proud of the deformation (usually given in mm) of the deformation that should appear at the same time as the diagram of the deformation that you show us.
I think these values must be very low in your case.
It's just a very exaggerated representation (or not) of the deformation in order to see if it corresponds for the meaning only to the requested deformation.
Explanations, the simulation is accurate but the representation is deliberately exaggerated by the software depending on the settings chosen or not by you.
In the results of the simulation, whether it is Von Mises, displacement or deformation, it is possible for everyone to define whether we want to conform to reality or have a deformation 3 times greater or if it is in automatic (default) it can go up to 1000 times the real deformation. The purpose of the parameterization is to see what would be a deformation with a slightly higher load without having to redo a new simulation (which is quite long sometimes. Often when the displacements are small 0.4 mm you don't see anything on the screen. By artificially exaggerating the deformation, it gives an idea.
How to change the setting: in the Result == section> right-click on Constraints ==> Change the definition ==> Distorted with the following choices : Automatic, full scale, user-defined.
In summary, even if the deformation is graphically exaggerated,the results do not change.
On the other hand, I advise you, if you allow it, in right click ==> parameters ==> graphics options (at the very bottom not to use scientific (confusing to those who are not careful in the graphic results, try with "displacement") but to select normal.
The stains are also used in the model to see the stress concentrations. If you make an animation you see the colors of the part at rest without load up to the max deformation. You have a complementary tool which is the "design dissection" which allows you to see the stress concentrations within the material. Whereas the 3D colored view only shows surface stresses which are often false excessive stresses if the mesh optimization is not done correctly or if the part does not have a radius or chamfers in the corners.
Note that with Von mises you have a direct reading of the Max resistance of an S235 (for example) as soon as you have an excessive stress then appears a small black arrow which locates the max resistance, allowing you to judge if this maximum stress is acceptable or not (be careful we are in the case of a static study in dynamics it would be different.
So when I change the definition, I put a custom value. This value corresponds to the weight in Kg. For a load of 2500 Kg, I just have to put 2500. Which makes 2500 * 9.81 N.
It worked, I can visualize the deformation according to the load exerted on my part.
On the other hand it worked for a while, and then now I have this error message:
"Excessive travel has been calculated in this model. If your system is properly constrained, please use the Long Trips option to improve the accuracy of calculations. You can also continue with the current parameters and determine the causes of these movements. Click 'Yes' to use the Long Moves option. Click 'No' to use small movements. Click Cancel to complete the resolution."
It is impossible to answer without seeing the parameters used, in particular the fixed points.
If you have large movements, it is because your room is badly constrained. From what I see in the first image published, you have made the bearing and an axis on each side solid. You actually have a bearing charge but you are not using it, so your simulation can only be wrong. But this connection is only made on half a shell, which means that in real life, during the max bending, the axis would only rely on a portion of a circle so as not only on one point. In addition, curiously, the tube deforms but we do not see any red color at the level of the axes embedded in the bearing while it is seriously deformed, probably beyond its elastic limit
For large displacements, it is likely that beyond a certain deformation the piece is no longer the necessary supports on one side and becomes mono support like a fishing rod held in the feverish hand of the big fisherman.
Between us, doing a simulation on a single element of the trailer axle doesn't make much sense, especially since you are using a force instead of a load (this can be seen at first glance on the deformation). Moreover, a trailer axle does not look like this at all and the efforts are not what you indicate in the first post
ANYWAY ! If you want to go further and get reliable results, if you have the 2019 version or lower, post your ASM with the Pack and Go function and specifying to attach the result of the simulation. And above all, make a sketch, even freehand, of the trailer as you imagine it or a photo of a model on the Net.
I often say here that simulation (just like mechanics) is not voodoo and therefore we cannot rely on occult forces and the spirit of ancestors to achieve these ends. ;-) ;-) ;-).