Jorgen
2008-01-28, 06:34
The most recent extended functionality release of ABAQUS (v6.7-EF) contains a new model called the FeFp model. A lot of people have asked me about how this model works, and since the ABAQUS manuals do not provide much information I decided to performe a study of how this new model works for elastomers and thermoplastics. You can read the results from this study here (http://polymerfem.com/polymer_files/FeFp_model_evaluation.pdf), or in the attached document.
In summary, the FeFp model is claimed to be able to "predict permanent set in filled elastomers and thermoplastics". My study, however, shows that the FeFp model is not able to accurately predict the response of either elastomers or thermoplastics. In fact, the predictions from this model are not very different from the old metal plasticity models, which are known to not work well for polymers. I have also shown that much more accurate material models exist, for example the dynamic Bergstrom-Boyce model (DBB (http://polymerfem.com/index.php?pageid=umats)) for elastomers, and the three-network model (TNM (http://polymerfem.com/index.php?pageid=umats)) for thermoplastics.
In summary, the FeFp model is claimed to be able to "predict permanent set in filled elastomers and thermoplastics". My study, however, shows that the FeFp model is not able to accurately predict the response of either elastomers or thermoplastics. In fact, the predictions from this model are not very different from the old metal plasticity models, which are known to not work well for polymers. I have also shown that much more accurate material models exist, for example the dynamic Bergstrom-Boyce model (DBB (http://polymerfem.com/index.php?pageid=umats)) for elastomers, and the three-network model (TNM (http://polymerfem.com/index.php?pageid=umats)) for thermoplastics.