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Characterization of Mode I and Mode II Interlaminar Fracture Toughness in CNT-Enhanced CFRP under Various Temperature
Burak Yenigun1, Muhammad Salman Chaudhry1, Elli Gkouti1
1Department of Mechanical Engineering, York University, Toronto, ON M3J 1P3, Canada.
Nanomaterials (Basel, Switzerland)
|June 10, 2023
Summary
This study shows that adding carbon nanotubes (CNTs) to carbon-fiber-reinforced polymers (CFRP) improves fracture toughness up to an optimal CNT amount. Fracture toughness increases with loading rate and temperature, but Mode II toughness peaks at room temperature.
Area of Science:
- Materials Science
- Polymer Composites
- Nanotechnology
Background:
- Carbon-fiber-reinforced polymers (CFRP) are advanced materials with applications in various industries.
- Enhancing the interlaminar fracture toughness of CFRP is crucial for improving structural integrity and durability.
- Carbon nanotubes (CNTs) offer potential for matrix toughening in polymer composites.
Purpose of the Study:
- To investigate the impact of temperature and loading rate on Mode I and Mode II interlaminar fracture behavior of CNT-CFRP.
- To determine the optimal carbon nanotube (CNT) loading for enhanced fracture toughness in CFRP.
- To characterize the toughening mechanisms induced by CNTs in the epoxy matrix.
Main Methods:
- Fabrication of CFRP with varying CNT areal densities in the epoxy matrix.
- Experimental testing of CNT-CFRP samples under different loading rates and temperatures for Mode I and Mode II fracture.
- Fracture surface analysis using scanning electron microscopy (SEM) imaging.
Main Results:
- Interlaminar fracture toughness (Mode I and Mode II) increased with CNT loading up to 1 g/m², then decreased.
- Fracture toughness showed a linear increase with loading rate for both Mode I and Mode II.
- Mode I fracture toughness increased with temperature, while Mode II toughness increased up to room temperature and decreased thereafter.
Conclusions:
- Optimizing CNT content is critical for maximizing the toughening effect in CFRP.
- Loading rate significantly influences CNT-CFRP fracture toughness, with a positive correlation observed.
- Temperature affects Mode I and Mode II fracture toughness differently, highlighting the complexity of environmental influences on composite performance.
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