How to represent suspension springs for simulation?

[Jim Steinmeyer]

I am looking for a realistic method to represent a suspension and springs on a trailer for use in simulation. In the screen shot below I have the tongue on a roller slider and the center hangers of the suspension fixed. I then placed springs under the outer two suspension hangers. I don't think that is the correct way to deal with it though. Do I create a beam between the front and middle hanger and another one between the middle and rear hanger with a fixed point in the center of each where the axle would be? I assume one of those fixed points would also need to be a slider. How do I then get those new beams to represent springs without having a deformation issue? I guess I might be able to set the properties of the beam, maybe?
And yes I know I should be using symmetry, but when I use the center line and cut the model in half the symmetry fixture tells me that the cut surfaces must be on the same plane, even though they were cut with a single line.

TIA

[JuTu]

There is an option to set a body or part to be rigid which atleast to my understanding (and guessing) leaves it out side the scope of study but could be used to transfer forces.

[MJuric]

I am looking for a realistic method to represent a suspension and springs on a trailer for use in simulation. In the screen shot below I have the tongue on a roller slider and the center hangers of the suspension fixed. I then placed springs under the outer two suspension hangers. I don't think that is the correct way to deal with it though. Do I create a beam between the front and middle hanger and another one between the middle and rear hanger with a fixed point in the center of each where the axle would be? I assume one of those fixed points would also need to be a slider. How do I then get those new beams to represent springs without having a deformation issue? I guess I might be able to set the properties of the beam, maybe?
And yes I know I should be using symmetry, but when I use the center line and cut the model in half the symmetry fixture tells me that the cut surfaces must be on the same plane, even though they were cut with a single line.

TIA

Granted I do not wholly understand what you're trying to do here but the first thing that popped into my head was to use virtual walls. You can set how much force the wall will take in perpendicular and parallel directions. I've done this with other simulations where I knew how the material the part was pushing against would act/respond so maybe it's a reasonable way to represent a spring although I have no idea how dynamic a virtual wall is.

[bnemec]

which component are you analyzing, the frame or the springs? You say you want to represent the springs but the image is all "rigid" frame.

What exactly are you looking to solve for?

[Jim Steinmeyer]

I am attempting to analyze the frame.
The rectangle blocks on the side of the frame represent the hangers that the leaf springs are attached to. There is one spring between the front and middle hanger and another between the middle and rear hanger. I could model a beam in those locations and give it the properties of the spring, I think. Then create a point in the center of each beam to fix representing the tires/axles that contact the ground. But is that getting too complex or needed? The spring ends are attached to the middle hanger with bolts allowing it to pivot with no translation. The other ends are allowed to slide in the hangers.
I suspect there will be some flex between the hangers and it will probably be different due to the springs, but is it significant enough for concern? Is this a place where it can be simplified? I could place the center hanger on a spring as well, but then how do I make this frame constrained enough for analysis? I guess that is where I was going with my spring questions.

[Jim Steinmeyer]

I guess maybe I should add that this is an agricultural trailer that we are looking at with the blocks on the sides that have the constraints (fixed and springs) added are the contact locations for the 2 axle suspension. I have been in this so much that I forget that it isn't clear to those not building trailers what this is.