Multiscale Analysis of Reinforced Concrete Frames with Embedded Metamaterials Under Progressive Collapse

Area of Science:

• Structural Engineering
• Materials Science
• Computational Mechanics

Background:

• Progressive collapse is a critical failure mode in reinforced concrete (RC) structures.
• The use of architected materials, like auxetics, to enhance RC structural resilience is underexplored.

Purpose of the Study:

• To numerically assess the feasibility of using auxetic metamaterial inserts in RC beam-column joints to mitigate progressive collapse.
• To investigate the mechanism by which auxetic inserts improve structural performance.

Main Methods:

• Development of a hierarchical multiscale framework coupling macroscale structural analysis with mesoscale fracture simulations.
• Utilizing a hybrid voxel-Voronoi discretization strategy for detailed analysis.
• Validation of baseline models against experimental data for conventional RC specimens.

Main Results:

• Auxetic inserts generate localized confining stress, promoting crack bifurcation and distributing damage.
• Simulations predict a 25% increase in load redistribution capacity and a 20% enhancement in deformation ductility for auxetic-enhanced RC configurations.
• The auxetic mechanism delays concrete crushing and crack coalescence.

Conclusions:

• Auxetic metamaterial inserts show significant potential for improving the robustness of RC joints against progressive collapse.
• The findings provide a computational foundation for material-by-design strategies in structural engineering.
• Experimental validation is recommended to confirm the predicted performance enhancements.