Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids.

Area of Science:

• Materials Science
• Mechanics of Materials
• Nanotechnology

Background:

• Macroscopic mechanical behavior of open-porous cellular materials depends on microscopic cell wall properties.
• Compressive response is characterized by linear elastic, plateau, and densification regimes.

Purpose of the Study:

• To present a constitutive model for open-porous cellular materials.
• To capture linear elastic regime, pore-collapse, and hardening during densification.
• To validate the model against nanoporous materials.

Main Methods:

• Modeling the network as idealized square-shaped cells with cell walls undergoing bending and buckling.
• Decomposing the network into active and collapsed networks based on damage criteria (elastic buckling or irreversible bending).
• Quantifying densification onset by the intersection of stress-strain curves of the two networks.

Main Results:

• The model successfully captures the linear elastic regime, pore-collapse, and hardening upon densification.
• Parameter sensitivity analysis demonstrates the model's capability to represent diverse material characteristics.
• The proposed model shows good agreement with experimental data from two types of nanoporous materials.

Conclusions:

• The developed constitutive model accurately predicts the compressive response of open-porous cellular materials.
• The model provides a framework for understanding and designing materials with specific mechanical properties.
• Validation confirms the model's applicability to real-world nanoporous materials.