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Modeling Brittle Fractures in Epoxy Nanocomposites Using Extended Finite Element and Cohesive Zone Surface Methods
John J S Biswakarma1, Dario A Cruz1, Erich D Bain2
1Department of Chemical Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
Polymers
|October 13, 2021
Summary
This study accurately predicts fracture toughness in epoxy nanocomposites using advanced modeling techniques. These methods, including cohesive zone and extended finite element methods, offer reliable fracture analysis with minimal parameters.
Area of Science:
- Materials Science
- Mechanical Engineering
- Computational Mechanics
Background:
- Epoxy nanocomposites offer enhanced mechanical properties but require accurate fracture analysis.
- Understanding mode I fracture is crucial for predicting material failure in structural applications.
Purpose of the Study:
- To quantitatively assess mode I fracture toughness in epoxy nanocomposites using computational modeling.
- To validate linear elastic fracture mechanics against experimental data for brittle and toughened materials.
Main Methods:
- Modeling quasi-static single-edge notched bending (SENB) tests using cohesive zone (CZS) and extended finite element methods (XFEM) in Abaqus.
- Incorporating empirical material tensile data and a linear softening traction-separation law (TSL).
- Initiating damage simulation when crack tip nodes reach experimentally measured yield stress.
Main Results:
- Excellent quantitative agreement between simulated and experimental mode I fracture toughness for epoxy nanocomposites.
- XFEM model demonstrated predictive capability without adjustable parameters.
- CZS model showed high accuracy with minimal parameter optimization.
Conclusions:
- Linear elastic fracture modeling coupled with empirical data provides a robust framework for predicting nanocomposite fracture behavior.
- Continuum methods like CZS and XFEM are effective for mode I fracture analysis with few independent parameters.
- The study validates computational approaches for designing and analyzing advanced epoxy nanocomposites.
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