| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
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Materials Aging and Compatibility: Experimental and Computational Approaches to Enable Lifetime Predictions
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| Presentation Title |
Predicting Photo-Oxidative Embrittlement of a Semicrystalline Thermoplastic from Micromechanical Damage |
| Author(s) |
Kenneth Cundiff, Amine Benzerga |
| On-Site Speaker (Planned) |
Kenneth Cundiff |
| Abstract Scope |
Polymers chemically age by photo-oxidation when exposed to UV radiation, leading to embrittlement that limits their lifetime. In semicrystalline thermoplastics, photo-oxidation causes chain scission, chemi-crystallization, and microcracking, but microcracks are often ignored when formulating embrittlement criteria. To understand the role of microcracking in the photo-oxidative embrittlement of semicrystalline thermoplastics, a micromechanics-based continuum damage model is used to predict the strain-to-failure in photo-oxidized polyamide-6 (PA-6), where microcracks are represented as oblate voids. The strain-to-failure of PA-6 before and after photo-oxidation was determined by loading round notched bars to fracture. The model’s void growth and coalescence criteria depend on void volume fraction, aspect ratio, and spacing, which were determined using synchrotron tomography. The model was also used to predict failure by cavitation in unaged PA-6. The model successfully predicted the strain-to-failure in both unaged and photo-oxidized PA-6, indicating that both ductile failure and embrittlement by chemical aging are controlled by micromechanical damage. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Polymers, Modeling and Simulation, Mechanical Properties |