Radioss/hypermesh non-linear analysis of a roll cage

Altair Forum User

Hello,

I have some questions about RADIOSS/hypermesh.

I am trying to run some non-linear. So...I have a roll cage and I want to conduct a test on it. The real test consist of a applying a load through a circular pad (rigid, no deformable) with a given geometry to the main hoop and measure the deflection (the load is applied in vertical direction, downwards). To pass the test the deformation should be less than a given value. Apart of that information, I am interested in the maximum load carrying capacity of the roll cage. Therefore, I was thinking about creating a rigid wall (pad in the real test) and make it move to deform the main hoop (0.1m/S until the required displacement is reached). Finally plot force vs displacement, energy vs displacement and energy vs time.

Sounds very easy and strait forward process but I am having a lot of problems. It's my the first time working with RADIOSS and I'm struggling a lot with this non-linear simulations. I have problems even in the single steps:

- creating a rigid wall with a given geometry (circular, dia 200mm).
- providing the rigid wall with movement.
- Importing stress-strain curve.
- Creating the contact between the circular pad and the roll cage.
- Plotting the mentioned graphs.

So please, if anyone can help me I would appreciate a lot. I just need someone to tell me where can I find a tutorial where something similar to this is done or someone who explain me briefly how to run this simulation (guidance).

In the following link information regarding the real test can be found:

http://www.home.zonnet.nl/mfeijts/SCARB/rolli.htm

drawing 253-38 show the basic test configuration. The point 8.4 describe the loads. This is not exactly the procedure I have to follow (the circular pad in my procedure is smaller and the loads are higher) but it is a very good way to let you know my problem.

I have to follow the test in two different ways, using 3D elements and using 1D.

Cheers

Altair Forum User

eat,

You can create a circular plate, make this into a rigid body,

You can see Training Altair University > STRUCTURAL > ANALYSIS > PROJECTS (analysis) > Front Crash Box System
To create a rigid component first a deformable component (Rigid Wall), reproducing the geometry of the barrier, is modeled. Then a rigid body connection of all nodes of the barrier is created.

You can also refer to snap through roof and other such tutorials in this section of the training center.

These will also explain about contact definitions,

>https://www.youtube.com/watch?v=nbJstdvCMTg

>https://www.youtube.com/watch?v=gM93KXwhyos

>https://www.youtube.com/watch?v=4dB-FvflHm8

>https://www.youtube.com/watch?v=TvBBtCCr2Ns

>https://www.youtube.com/watch?v=ip3Oej-cHRM

>https://www.youtube.com/watch?v=6ZR0fpoFPXU

>https://www.youtube.com/watch?v=RWds5U1-4Ag

>https://www.youtube.com/watch?v=TkPWTMi8k7Q

>https://www.youtube.com/watch?v=f-VSLl_6_Jc

In chapter 2, at 40 minutes you have a clear procedure to import and apply the stress strain curve for a material, also RADIOSS, MotionSolve, and OptiStruct Tutorials > RADIOSS > Large Displacement Finite Element Analysis > Block Format > HyperMesh:
RD-3597: Cell Phone Drop Test using HyperMesh

HyperWorks Desktop Applications > HyperGraph 2D > HyperGraph 2D Tutorials:
Plotting Basics and more importantly, Training Altair University > VISUALIZATION > Getting started with HyperView/HyperGraph will give you all the information about plotting your postprocessing curves.

Altair Forum User

RADIOSS, MotionSolve, and OptiStruct Tutorials > RADIOSS > Large Displacement Finite Element Analysis > Block Format > HyperMesh:
RD-3595: Three Point Bending with HyperMesh

will be very helpful, like step 9 of creating rigid bodies and contact definitions, here the master node of a rigid body is applied an imposed velocity just as you need to apply movement to a rigid body