Progressive Damage

[nellie]

Hi,

I am looking for some kind of damage evolution model that I can introduce into a user defined material subroutine. I am studying PMMA/PC laminate structures under ballistic impact loading. I was looking in the literature , but could not find anything . Mostly failure models. Any suggestion of ideas or reading would be helpful.

[Jorgen]

My first question is why are you looking for a damage model if you are mainly interested in impact loading.
Would not a failure model be sufficient?

-Jorgen

[nellie]

I was not sure if a failure model will be sufficient to capture microcracks and their propagation. If you have any suggestions regarding failure models, I would be really interested in taking a look into the models.

[Jorgen]

What FE software are you using? Are you planning to simulate the microcrack nucleation and growth explicitly?

[nellie]

I am using LSDyna. Yes I am trying to simulate the microcrack nucleation and growth. I need some guidance as I want to simulate the experimental results which shows nucleation of cracks. Most of the papers report failure models and I was not sure if that would capture the microcracks. I am new to damage field and hence I am seeking advice.

[Jorgen]

You are trying to do something quite challenging. It can (probably) be done, but it is not an easy assignment.

It is easy to implement and use almost any arbitrary damage and/or failure model. I have experience doing this.
What is more difficult is to create a FE model in which you have the element capture the crack nucleation and growth.

-Jorgen

[nellie]

As you mentioned that you have used failure models, can you suggest some that you have used for polymers. I understand that capturing elementwise nucleation is challenging.

[O'Brien]

Well its a challenge that has been taken by him. But in my point of view it is not easy to do but every thing is possible and can be done if you have strongly aimed at your work.