Damage cluster distributions in numerical concrete at the mesoscale

Area of Science:

• Civil Engineering
• Materials Science
• Computational Mechanics

Background:

• Understanding concrete fracture mechanics is crucial for structural integrity.
• Mesoscale modeling provides insights into heterogeneous material behavior.
• Damage cluster analysis aids in predicting material failure.

Purpose of the Study:

• To investigate the size distribution of damage clusters in concrete under uniaxial tension.
• To analyze the relationship between damage cluster formation and material failure.
• To explore the influence of mesostructural parameters and loading conditions.

Main Methods:

• Finite-element method (FEM) for mesoscale concrete modeling.
• Simulation of aggregates within a mortar matrix.
• Dynamically inserted cohesive elements to model damage propagation and coalescence.
• Dynamic failure analysis.

Main Results:

• Damage cluster size distribution follows a power law near system-spanning cluster formation.
• The observed exponent aligns with percolation theory predictions.
• System-spanning clusters precede local decohesion and material failure.
• Crack surfaces show weak correlation with initial percolated damage structures.

Conclusions:

• Power-law scaling of damage clusters is a key indicator before concrete failure under tension.
• Percolation theory provides a relevant framework for understanding mesoscale damage.
• Mesostructural characteristics and loading rates influence damage evolution but not the fundamental scaling law.