Polymeric Materials Reinforced with Multiwall Carbon Nanotubes: A Constitutive Material Model

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Polymeric materials reinforced with carbon nanotubes exhibit complex behaviors like softening and residual strain under cyclic loading.
• Existing material models may not fully capture these phenomena, limiting their predictive accuracy for such composites.

Purpose of the Study:

• To modify an existing material model to incorporate softening and residual strain effects in carbon nanotube-reinforced polymers.
• To validate the enhanced model's accuracy by comparing its predictions with experimental data from uniaxial extension tests.

Main Methods:

• Modification of a pre-existing material model (Cantournet et al.).
• Inclusion of parameters accounting for softening and residual strain.
• Experimental validation using uniaxial extension tests on four reinforced polymer systems.

Main Results:

• The modified material model accurately predicts the behavior of the tested polymer composites.
• Maximum prediction errors were below 2.67% for BIMSM-MWCNT, 3.66% for NR-MWCNT, 7.11% for PB-CB, and 6.20% for SWCNT-reinforced PC/ABS.
• The model effectively captures the effects of loading and unloading cycles.

Conclusions:

• The proposed modified material model offers a reliable tool for predicting the mechanical response of carbon nanotube-reinforced polymers.
• The model's accuracy is demonstrated across diverse polymer matrices and carbon nanotube types.
• This work advances the understanding and modeling of advanced composite materials.