Having Issues with Dynamic Event and Quasi-Static simulations

[omar_zainabeden]

Hello there, I've been trying to figure this one out for a while now and I would appreciate your input. 

I'm new to Tool and Die design and I'm using Fusion simulation environments to help me come up with an optimal design to bend one of our parts. 

I tried both Dynamic Event simulation and Quasi-Static and I'm encountering issues with both. 

Dynamic Event: 

 Stress is rising up to 500 MPa upon making contact with the blank (flat part). I set the initial velocity of the punch tool to -0.001 m/s, I set a Transient Force using a Magnitude curve across time (0.01 s). The magnitude starts with 0 and ends with 100 tonforce (our machine capacity). The material for all components is nonlinear Standard Structural Steel.  Both the punch and die are set as rigid bodies with the necessary structural constraints. 

I don't understand why Stress is hitting 600 MPa outright. I tried tinkering with all the inputs but to no avail. I switched the study type to Quasi-Static as it might be the better suited environment for my application. 

Quasi-Static: 

The simulation is not even running with this one. I'm getting the following error "Error: we have determined there is no internal energy which implies there are no loads.
Cause: This error generally occurs when there is no contact between bodies or there are large gaps
between them. It can also occur when there is no loading." 

Please see attached picture. 

Your help is greatly appreciated. 

[henderh]

Hi @omar_zainabeden,

Would it be possible to share or attach the f3d file? We're eager to take a closer look at the exact study setups.

• File > Share File Link > Copy / paste the link here (ensure allow item to be downloaded slider button state is On)

Alternately,

• File > Export... > Autodesk Fusion Archive Files (*.f3d)

I suspect there may be a Contact property, such as Maximum Activation Distance that's causing the unexpected high stress (well away from contact zones) while the part is still practically 'floating in the air'. 

Best regards,

[omar_zainabeden]

Hi @henderh, thank you for the response. 

Please see attached. I'm not sure if this file will contain both of the studies. 

Let me know if you need anymore files. 

Thanks. 

[omar_zainabeden]

Hi @henderh, 

Did you get the chance to have a look at my model? 

I appreciate your help. 

[henderh]

Hi @omar_zainabeden,

My apologies, I did get a chance to look at the setup. However I became side-tracked and failed to create a timely reply. I appreciate the gentle reminder.

For the flat bar workpiece, it appears the exterior six faces are Fixed in all three translational Degrees of Freedom (the fancy term is 'full fixity'). Therefore those faces should be completely immovable in 3D space. There shouldn't be any displacement / deformation with this setup condition.

I'm not sure why in your screenshot, it does show deformation and the high stress. 

Hope this helps! Please let us know if you have additional questions, comments, or suggestion.

Best regards,

ps: Late on Friday the 31st, I forward'ed the f3z attachment update email to a colleague who is one of our SME's. I'll circle back if there's more info available.

[henderh]

I almost forgot to mention that we offer a Quasi-static Event Simulation tutorial which is similar to your punch & die setup that may be a useful reference:

• https://help.autodesk.com/view/fusion360/ENU/?guid=SIM-TUT-10

Hope this helps!