Introduction
Polyetherimide (PEI) is a thermoplastic material with excellent mechanical properties. In this article I will examine different material model options for this important material. I will specifically examine the Ansys TNM model, the Abaqus PRF model, and the PolyUMod TNV model. I picked these models since they are the most accurate for this class of materials. The classical plasticity models are not very useful for predicting the response of this material.
Experimental Data for PEI
The experimental data for the polyetherimide (PEI) comes with MCalibration, and you can add it using the “Add Virtual Test” button in the “Experimental Data” tab. The figure shows the experimental data that I will use the experimental data in the figure below.
I calibrated the following material models using the MCalibration software. Get your own free trial license.
Results: Ansys TNM
The figure below compares the predictions from the Ansys TNM to the experimental data. The average error in the model predictions (NMAD) is 19%. One of the main issues with this material model is that if cannot predict the stress softening after yielding.
Results: Abaqus 3 Network PRF (Yeoh + Power Flow)
The figure below compares the predictions from the Abaqus PRF model to the experimental data. The average error in the model predictions (NMAD) is 19%. One of the main issues with this material model is that if cannot predict the stress softening after yielding.
Results: PolyUMod TNV
The most accurate material model for the PEI is the PolyUMod TNV model. The average error in the predictions of this model is 11.5%. Very nice!
