A Stochastic Damage Model for Bond Stress-Slip Relationship of Rebar-Concrete Interface under Monotonic Loading

Area of Science:

• Civil Engineering
• Materials Science
• Mechanical Engineering

Background:

• The bond stress-slip behavior of the rebar-concrete interface is critical in structural engineering.
• Existing theoretical models often lack the incorporation of stochastic behavior, limiting their predictive accuracy for real-world scenarios.

Purpose of the Study:

• To propose a novel stochastic damage model for characterizing the bond stress-slip relationship of the rebar-concrete interface under monotonic loading.
• To address the limitations in current literature regarding theoretical models that incorporate stochastic behavior.

Main Methods:

• A micro-mechanical approach was employed to develop a microscopic damage model.
• The model incorporates parallel micro-elements, including spring, friction, and switch elements, with random failure thresholds for spring elements to represent micro-fracture randomness.
• Statistical damage mechanics was used to derive expressions for the mean and variance of the bond stress-slip relationship.

Main Results:

• The proposed model successfully captures the stochastic nature of the rebar-concrete interface's bond stress-slip behavior.
• Parameters of the model were identified using a genetic algorithm and validated against experimental data, showing good agreement.
• The model effectively characterizes the random behavior influenced by micro-fractures.

Conclusions:

• The developed stochastic damage model provides a robust framework for analyzing the rebar-concrete interface under monotonic loading.
• The micro-mechanical approach and statistical damage mechanics enable accurate prediction of bond behavior, considering inherent randomness.
• This research contributes a valuable tool for understanding and designing reinforced concrete structures with enhanced reliability.