Improving Lateral Stiffness of Composite Wall Systems Through Vertical Reinforcement

Location
Structure Type
Software Used

British Columbia
Reinforced Frame Structure
Abaqus Standard Implicit

Objective

To evaluate the structural performance of the composite wall system under reversed cyclic loading using finite element analysis (FEA), with a focus on enhancing lateral stiffness by introducing vertical rebar at varying spacings. The goal was to determine the most effective reinforcement strategy to improve seismic resistance while maintaining material efficiency.

Test Method: Amplitude of Reversed Cycle

Load vs Deflection

Lateral Stiffness of Composite Wall Systems: Physical Test

Lateral Stiffness of Composite Wall Systems Analysis

FEA model of Lateral Stiffness of Composite Wall Systems

Challenges

The wall system lacked sufficient lateral stiffness when subjected to cyclic loading. Evaluating structural response while excluding imperfections and natural fiber stiffness introduced uncertainty in achieving realistic and conservative performance predictions.

Solution

Three FEA models were created in Abaqus, comparing configurations with and without vertical rebars. Displacement-controlled cyclic loads per ASTM E2126/ISO 16670 were applied to assess stiffness enhancement via reinforcement.

Result

Adding rebars significantly improved stiffness. No rebar failure was observed. Rebar spacing at 4’ outperformed 8’ spacing and the bare frame, indicating effective enhancement of structural resilience under cyclic loads.

Key Results

Stiffness improved significantly with the inclusion of vertical rebars, especially at 4-foot spacing.
No failure observed in the rebars throughout the cyclic loading sequence.
The composite frame alone was insufficient in resisting lateral forces, confirming the need for added reinforcement.
The simulation adhered to ASTM E2126 / ISO 16670 protocol, validating real-world seismic performance predictions.

The study validated the role of simulation in structural optimization, reducing reliance on costly physical tests. The findings confirmed that strategic reinforcement can make composite walls viable for lateral load applications in building systems.