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Non linear analysis with sequential loads

Hi there,

 

i want to simulate the following model with SOL 101 with contact between body1 and body2:

model.png

The model containts 2 plates where one plate is loaded with a pressure load acting vertical and normal to the plate1. Now i want that this loadcase is calculated before also loading the plate2 with a force acting horizontal and longitudinal. Because with my current setup the normal force theoretically resulting out of the pressure load isn't acting because the force is moving the plate2 longitudinal so there is a stiffness change while trying to calculate the normal force. As result i will only see plate2 moving longitudinal without any deformation/contact pressure on plate1. If i simulate the same model without the force i will get nice deformation/contact pressure on plate1.

 

So how i can do this "sequential loading"?

 

Thank you very much for your help Smiley Happy

27 REPLIES 27

Re: Non linear analysis with sequential loads

Siemens Phenom Siemens Phenom
Siemens Phenom

When contact is present in the model, subcases are sequentially dependent by default.

 

Define contact (BCSET) in the global case

Define the pressure load in subcase 1

Define the pressure and force load in subcase 2

Re: Non linear analysis with sequential loads

Hi JimB,

 

thank you for your help. I researched a lot but didn't find that fact. So i tried it and here are the results:

s1.pngs2.pngSubcase1 will show me the deformation as a result of the pressure load. Subcase2 will show me plate2 slipped  in longitudinal direction and a little bit of deformation as a result of the pressure load. So it seems to be working. But the slipping is too much, also if i reduze the force. I think the normal force is not acting at its maximum. May do i have to set up some parameters?

Re: Non linear analysis with sequential loads

Genius
Genius

Dear @PuddingBaer91,

Firs of all, I do not understand why are you talking of a non-linear solution if you use SOL101 since is a linear solver.

 

Anyhow, if I understood well, you want to create a sequential loading as follow: first you want to apply the pressure, and then you want to add the force (keep constant the pressure). Is it correct?

 

If yes, you probably need a non-linear solution (eg 106 or 601). In this way, you can controll, as you want, the force or pressure value during each time-step. Hence you can switch on gradually the pressure and keep constant, and then switch on the force and at the end of the simulation you get you final result.

Please tell me if I do not understand the problem correctly.

Regards,
A

Re: Non linear analysis with sequential loads

Hi AlbertoM,

thank you for your help.
Since contact is a phenomen which exist in the most cases the linear solver 101 also can handle non linear contact problems. But the solver only can handle simple contact load cases, no dynamic things. Then we need solver 601.

Cause i only want get the deformation because of the force while the bodys coupled because the normal force and static friction the solver 101 should handle this.

Imagine i could also glue the bodys together instead of applying pressure, i also will get the deformation but the real case i want to model is with pressure shown in my pictures...

Re: Non linear analysis with sequential loads

Genius
Genius

I agree with you about the contact non-linearty  in SOL101. (I was surprised when I discovered it!) Smiley Happy

 

Anyhow I think that if you want to catch the sequental loading, a 601 solver is the only solution.

 

Edited text: the SOL601 is not a real dynamic solver! The time is "fictitious". Basically SOL601 is a static non-linear solution. Nothing to do with time-domain solutions and dynamic solvers (e.g. SOL701)!

Re: Non linear analysis with sequential loads

Mee too Smiley Very Happy

Okay i tried solver 601 already but i not saw an option to say load body1 with pressure and calculate the contact force and after that apply the force...

Yeah i know we need sol701 or so. I don't know the number Smiley Very Happy

Re: Non linear analysis with sequential loads

Genius
Genius

In a "SOL601,106 Advanced Nonlinear Static" you need to specify timestep, and then you need to go in the you load edit->table and you create you own loading profile of load vs the time step. That is done for both force and pressure.

 

See some videos on Youtube/read some references to learn how it works!

There are a lot of video that show you how the simulation is created, you need just to search on google 10 min.

 

Maybe you can start from this: https://www.youtube.com/watch?v=Px92mu-SN4Y
As you can see there is a specification of the "fictitious" time and then the loads are controlled over the time.

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Re: Non linear analysis with sequential loads

Thanks Alberto, sounds interesting but i don't know how to do this. Do you have some stuff where i can read how to do this?

Thank you

Re: Non linear analysis with sequential loads

Genius
Genius

I hope that you learned how "SOL601,106 Advanced Nonlinear Static"  work according to the previous tutorial link, and you solved the problem.

In that case, consider to accept the solution in order to let the other users that this discussion is solved.

Regards, A