Hello everyone, as part of a project I have to do RDM on a catia assembly and I always get the message: "singularity detected in the translation (pivot too small)". I know that we have to constrain the assembly by adding rigidity or virtual parts. I disabled and hid the other parts of the assembly hoping that there was no interference. Here there are two parts, the fixing and the arm. My links are (from left to right): - Recessed connection for the interior surfaces of the two plates that will be attached to a beam - Creation of two rigid parts to put 2 pivot links (one for each part) - Creation of a virtual contact piece between the two end clevis (because another arm comes to fit)
Then a force of 1500N downwards to simulate a small load.
Here are the results in photos.
There should be a brake between the attachment and the arm to avoid rotation according to z for nothing, but I don't know how to represent it. If you have any suggestions, I'm all for it.
Could you post your images in a ZIP because there we don't see enough of the images.
Regardless of what I see from your setup, there is no interest in having a rig to test the tonearm in my opinion; even if Catia is hyper-powerful. Testing the part in isolation is sufficient under certain parameterization conditions.
You can test what looks like an arm (with pivot links) on its own if you don't want to see the deformations on the left part.
Moreover, we don't know anything about what you call a brake according to Z.
You either have to work on the part alone but on the condition that you set up all DDLs that can cause deformation.
If you are still working on the assembly, you need to have a clear vision of what holds the part straight and there again with all the possible DDLs of what holds this part straight.
So as you will see, my project has to lift large diameter parts with a mass of 250 kg with an arm that can extend up to 2.6m (from the middle of the beam to the center of the largest object which is 1.3m in diameter). The pivots are oriented vertically (z-axis). The fixing is screwed to the beam. And an electric hoist would lift the part and a handling tube over a low wall, and then use the pivots to fold the project and then place the part on the other side.
"" "singularity detected in the translation (pivot too small)". "" either it's because the axis doesn't respect the minimum size for the effort, (otherwise you are beyond the elasticity lite (and even that you have reached the ruin criteria if CATIA gives this information), or there is another reason that I can't analyze without seeing any parameterization conditions. Solidworks does not provide the information in this form. But in view of the drawing, I lean more towards the criteria of ruin.
In your case, you should use a joint with the four pieces in petrol blue.
You will also have to do several simulations with different positions of the stems because you have positions where you will have maximum spills.
Did you design this set????
I'm a little scared when I see the complete model.
If a colleague from the forum who knows CATIA is willing to help you, that would be good: because the first thing to do will be to see how you have set up all the connectors and how you have managed your masses remotely.
