weakness of the Arruda-Boyce model in Abaqus?

[hhspiny]

Hello Jorgen

I understand the Arruda-Boyce model implemented in Abaqus is closely related to the hybrid model. Could you please point out any reference or give some comment on the weakness of the abaqus implementation?

I need to model the sintering process of PTFE, and want to decide if I can use the Abaqus model or I need to either implement/buy the hybrid model which I believe is superior. I perceive my difficulties would be temperature dependent behavior, and the coupling of hyperelasticity with visoelasticity. more problem will come during the heat up again after cooling down above Tg. Being in industrial R&D environment, there is room for inaccuracy, but not much room for wrong approach. thank you

Hansong

[Jorgen]

Hansong,

There is some confusion about the names that are given to various models. Arruda and Boyce wrote a few papers together and in particular developed two interesting models. One model is a hyperelastic model, which is also called the 8-chain model. The other model is a viscoplasticity model for glassy polymers. The 8-chain model is implemented in ABAQUS, but the Arruda-Boyce viscoplasticity model is not implemented in ABAQUS.

Some years ago I developed a model with M.C. Boyce that is now implemented in ABAQUS. This model is often called the Bergstrom-Boyce (BB) model, and can be activated in ABAQUS using the *Hysteresis command. The BB model was developed for elastomer-like materials.

The Hybrid model (HM) is a a new advanced model for thermoplastics that is not available in ABAQUS.

I also recently developed a model for predicting the large-strain temperature behavior of PTFE. This model is called the dual-network fluoropolymer (DNF) model, and is not available in ABAQUS.

Papers discussing the BB, HM, and DNF models are available for download (http://www.polymerfem.com/modules.php?name=Downloads).

Based on your description, I think that the DNF model is likely to perform quite well for your application.

- Jorgen

[hhspiny]

thank you Jorgen. It was very helpful to understand the great work you have done. I probably need to fresh up my knowledge with the HM and DNF model you developed. Particularly, do you happen to have more data/test cases that you can share for the DNF model for PTFE. We do a lot of PTFE here for medical industry, and I really don't have any good tool to model it, espeically when temperature effect is added.