Learning Forum

[shisyphus]

I am trying to demonstrate peeling on Static Structural (refer to the diagram below).

I use Fracture > Contact Debonding at the interface of green and red bodies to model the peeling behavior. The issue is that the simulation does not converge if the force is too large resulting in complete peeling. I was wondering if there is a way to terminate the simulation at this point?

To add more information about the model, the goal is to measure how much force is required for complete peeling. As a different approach, I also tried applying displacement instead of force and measuring the force reaction. However, for some reason, the simulation takes much longer and also tends to not converge when the red and green bodies are completely detached.

Any suggestion on simulating complete peeling without having any convergence issue? I am attaching the simulation file for your information.

[jj77]

- It is good that you are trying to use displacement rather than force. This helps especially when the beam detaches and wants to fly away (due to force), making convergence very difficult.

- I would thus apply an enforced displacement gradually (see image below). Say in 30 steps (step of 2E-6 m up to 6E-5 m).

- Finally in order to do that increase the number of steps (30) is the analysis settings, and change the parameter as shown below, Also use soft springs as this will stabilise the model and prevent it from wanting to move in any other directions (see settings below).

On another point this part is really small (~-0.0002 m), perhaps check units and dimensions (perhaps it is that small).

 

[shisyphus]

Thanks jj77! I made the suggested changes and the simulation started converging much faster with a solution output that makes much more sense.

I have been debugging this for a while and never thought about increasing the number of steps. I once tried increasing the number of substeps though. Could you explain what is the difference of increasing number of steps vs. substeps? e.g, the difference between the following two analysis settings?

Case 1:  vs. Case 2: 

[jj77]

My main background is with another software where different terms are used for this, so I would just confuse you.

 

If you search for steps and substeps on the internet you will find some good info I am sure.

 

One link that is good is: http://www.padtinc.com/blog/the-focus/you-dont-wanna-step-to-this-breaking-down-loadsteps-and-substeps-in-ansys-mechanical

 

Also start a new question about this, since it will be easier for others to give you feedback. Also consider clicking on answered so this post can be "closed", and you can write another one about steps.