Numerical investigation of seismic performance and size effect in CFRP-reinforced concrete shear walls

Researchers have explored the potential of carbon fiber reinforced polymer (CFRP)-reinforced concrete composites to overcome the brittle failure and residual deformation commonly observed in conventional shear walls during seismic events. Published in Smart Construction Materials and Design, this study leverages the superior strength-to-weight ratio, corrosion resistance, and self-centering capability of CFRP to address post-earthquake reparability challenges. By numerically analyzing 28 CFRP-RC shear wall models under varying shear span ratios, horizontal reinforcement ratios, and height-to-thickness ratios, the research evaluates critical seismic performance indicators including hysteretic behavior, strength degradation, ductility, and residual deformation. A refined size-effect correction model, integrating CFRP strain distribution characteristics, is proposed to address existing limitations in seismic performance prediction—paving the way for more resilient, damage-tolerant, and performance-based structural designs in earthquake-prone regions.

This study uses finite element numerical simulation to systematically investigate the seismic performance of carbon fiber reinforced polymer (CFRP) reinforced concrete shear walls. A three-dimensional mesoscale finite element model was developed using Abaqus, incorporating nonlinear damage behavior of concrete, linear-elastic properties of CFRP tendons, and bond-slip effects at the tendon-concrete interface.

1. Material Constitutive Models

1. Concrete: The Concrete Damaged Plasticity (CDP) model was employed to accurately simulate the damage evolution under alternating tension and compression.
2. CFRP tendons: The brittle fracture characteristics of CFRP tendons were represented using a linear-elastic constitutive relationship.
3. Interface behavior: A nonlinear contact model was used to capture bond degradation and slip effects on global structural performance.

2. Key Parameter Analysis

The effects of key design parameters—height-to-thickness ratio, shear span ratio, and horizontal reinforcement ratio—were analyzed through low-cycle reciprocal loading simulations. Structural performance indicators such as ductility coefficient, stiffness degradation, strength degradation, energy dissipation, and residual deformation were evaluated. Main findings include:

1. Height-to-thickness ratio: An increase significantly reduces ductility and energy dissipation. The hysteresis curves exhibit shear-dominated characteristics, and plastic development is limited.
2. Shear span ratio: A low ratio leads to shear-dominated failure, rapid stiffness degradation, and weakened hysteretic performance.
3. Horizontal reinforcement ratio: Moderate increases improve ductility and load-retention capacity. However, excessive reinforcement can cause stress concentration and localized instability.

3. Size Effect and Correction Formula

The study demonstrates that wall geometry—particularly height-to-thickness ratio—significantly influences crack patterns, failure modes, and hysteretic behavior. As the height-to-thickness ratio increases, cracks become more unevenly distributed, failure transitions from global flexure to localized shear, hysteresis area decreases, and energy dissipation capacity is reduced. Additionally, larger wall sizes accelerate stiffness degradation and increase residual deformation.

To address these effects, a size effect correction formula considering height-to-thickness ratio was proposed. This formula improves the accuracy of ductility and strength predictions across varying wall sizes and offers a theoretical basis for seismic performance evaluation of large-scale shear walls in practical engineering.

This study reveals the mechanisms by which CFRP reinforcement configuration and geometric scaling affect seismic behavior. The proposed correction formula significantly enhances prediction accuracy and provides a technical foundation for reliable implementation in seismic zone applications. Future work will focus on experimental validation and optimization of dynamic response analysis under multi-dimensional seismic loading.

This paper “ Numerical investigation of seismic performance and size effect in CFRP-reinforced concrete shear walls” was published in Smart Construction.

Li B, Li D, Chen F, Jin L, Du X. Numerical investigation of seismic performance and size effect in CFRP-reinforced concrete shear walls. Smart Constr. 2025 (1): 0007, https://doi.org/10.55092/sc20250007.