Discrete Element Modeling of Concrete Under Dynamic Tensile Loading

Area of Science:

• Structural Engineering
• Materials Science
• Computational Mechanics

Background:

• Concrete is vital for critical infrastructure, necessitating understanding its behavior under extreme dynamic loads.
• High strain rate sensitivity of concrete in dynamic tensile loading is critical for structural safety.
• Existing continuum models have limitations in capturing fracture mechanisms in cohesive materials.

Purpose of the Study:

• To develop and validate a macroscopic 3D discrete element model for simulating concrete's dynamic response under extreme loading.
• To incorporate physically grounded strain-rate dependency into local cohesive laws for inter-element interactions.
• To assess the model's capability in predicting concrete failure characteristics at high strain rates.

Main Methods:

• Development of a macroscopic 3D discrete element model.
• Incorporation of strain-rate dependency into local cohesive laws.
• Calibration under quasi-static loading and validation through simulation of spalling tests at strain rates of 30-115 s⁻¹.

Main Results:

• The discrete element model accurately reproduced experimental outcomes, including rear-face velocity profiles.
• Simulations effectively captured failure characteristics of normal-strength concrete under dynamic tensile loading.
• Model validation under high confining pressure was previously established.

Conclusions:

• The discrete element method, with the proposed strain-rate dependent cohesive laws, is a capable tool for modeling concrete under extreme dynamic loading.
• This validated model enhances predictive capabilities for structural assessment and resilient design of critical infrastructure.
• The study reinforces the utility of discrete element modeling for understanding complex material behaviors in engineering applications.