SW Piston Raised Plate Simulation + Gravity

Simulation Dynamic kinematics
,
1

Hello

I'm looking to make a simulation of a platter (see image) on Solidworks. In reality, my platter is lifted by jacks, so I modeled them by pistons (1 at each corner). I would like to know how this platter deforms and how much moves when the 4 cylinders mount it and when gravity is applied to my assembly. I have carried out several simulations (static) but I have some problems:

- When I apply a force of 1500N on each inner piston (in contact with my plate to be able to lift it) and gravity: the displacement caused by gravity is much greater than that caused by the 4 pistons to such an extent that I have the impression that they do not move.

- When I force the 4 inner pistons to move 100cm upwards + gravity: two of the 4 pistons do it correctly and the other two deform in a very strange way (see image) while the constraints of my assembly are the same for the 4 and I impose the same displacements on them. Does anyone know where my problem could come from?

PS: my top plate is made of aluminum, my 4 pistons are made of alloy steel. I made the 4 inner pistons rigid and fixed the 4 outer ones in order to better model a slide and my structure weighs about a hundred kilos.

Thanks in advance,


assemblage.png
2

Hello

I have the impression that you want to do two incompatible things

Already you are talking about static simulation and at the same time something that makes you think of a dynamic simulation.

So without doing any calculations we see that you have four support points represented by your cylinders.

If you put fixed points that it wouldn't change anything.

In addition, each cylinder alone can lift 152 kg of grocer.

If you divide the weight of your 200 KG chainring divided by four support points, that's 50 kg to be lifted per piston (per support point, in other words, cherry stems).

Finally, just looking at your PNG file, I don't see how gravity could significantly distort your structure, which looks pretty strong as it is when empty.

After your concern seems to be more a problem of arching than a problem of deformation under its own weight (200 kg is nothing unless your tubes are ultra-thin and even then) since you seem to want to test your side slides.

Then the problem simply becomes a question of the piston. Either they are hydraulic cylinders and if they have the correct balancing regulators then the four cylinders will rise without deforming your structure. If they are pneumatic cylinders, it is a little more complicated to balance and therefore the risk of arquebutment is greater because of the ratio between the height of the slide and the length of the plate.

So in my opinion no need to do a simulation as long as you don't have the fixed technical solution for your jacks.

If you can't balance your jacks according to the rules of the art, it will block by arquebut, and there is no need to do a simulation in my opinion.

At your disposal to discuss it.

Kind regards

 

3 Likes
3

Hello

Thank you for your answer,

I don't really understand why my problem is reminiscent of a dynamic simulation. My strengths are independent of time, so this is a static simulation, right? In addition, I had tried to do a dynamic simu but the study took way too long to execute.

And yes, I know that I put a lot of force on each cylinder, it was precisely to see if they could lift my structure and "counter" gravity. In fact, I try to choose jacks that can lift it.

4

Hello

For your jacks, if you put a power X2 to the total weight, it's enough. Because it will prevent you from breaking (ruining) everything if by misfortune one of the sides of your board were to block for any reason.

I think that as I told you, your main risk is the arquebut. So more than the choice of the verion, which is quite simple, it is the servo system of the four cylinders that will be cotton.

If you are not limited in budget and if the speed of the movements is not too fast, I suggest you look at electric jacks or screw jacks connected by shafts and action by a single motor. There, whatever you do, you won't have an arquebut.

Quick question :-) your tray has no other additional load??? What is the total travel of your cylinders??? What do you put on it???

Kind regards

2 Likes