A Damage Model of Concrete including Hysteretic Effect under Cyclic Loading

Area of Science:

• Civil Engineering
• Materials Science
• Computational Mechanics

Background:

• Concrete exhibits complex nonlinear behaviors under cyclic loading, including hysteresis, stress softening, stiffness degradation, and irreversible deformation.
• Accurate modeling of these phenomena is crucial for predicting concrete structure performance, especially under seismic or repeated loading conditions.
• Existing models may lack the ability to fully capture the intricate stress-strain relationships and hysteresis loops characteristic of concrete.

Purpose of the Study:

• To develop a novel, computationally efficient damage model for concrete.
• To accurately represent complex nonlinear behaviors such as hysteresis, stress softening, stiffness degradation, and irreversible deformation under cyclic loading.
• To provide a flexible and easily implementable model for concrete structures.

Main Methods:

• The model transforms multiaxial stress states into a uniaxial state using equivalent strain.
• It incorporates distinct uniaxial stress-strain curves for tension and compression to account for concrete's asymmetry.
• Hysteresis effects are captured through established unloading and reloading paths, independent of curve shape.

Main Results:

• The model successfully reflects complex hysteresis phenomena and nonlinear behaviors of concrete.
• It simplifies multiaxial stress to uniaxial strain with minimal parameters and a simple mathematical form.
• Numerical results align well with experimental data from three-point bending, cyclic loading tests, and seismic simulations.

Conclusions:

• The proposed concrete damage model is reliable, correct, and demonstrates strong generality and flexibility.
• Its concise form facilitates easy implementation in engineering practice.
• The model effectively simulates concrete's response under various loading conditions, validated by experimental and simulation data.