What the study found
The study found that an advanced single-strut macro-model could reproduce the nonlinear behavior of reinforced concrete frames with lightweight infills. The model was calibrated for hollow clay brick, gypsum block, and autoclaved lightweight concrete systems and showed errors below 10% in lateral capacity and initial stiffness.
Why the authors say this matters
The authors conclude that the proposed modeling strategy is a reliable tool for performance-based design and analysis. They also say it can help engineers run parametric studies and assess the seismic suitability of different infill systems with less time and cost than full-scale testing.
What the researchers tested
The researchers implemented a single-strut macro-model in SAP2000, a structural analysis program, and added material-specific nonlinear axial hinges. These hinges were calibrated against full-scale experimental data from Cai et al. to represent crushing, shear-sliding, and slip-hardening behavior in the three infill types.
What worked and what didn't
The calibrated model showed high predictive accuracy, with lateral capacity and initial stiffness errors below 10% for all three systems. In the seismic comparison, hollow clay brick infills increased initial stiffness by 471% but failed in a brittle way, autoclaved lightweight concrete panels showed ductility of μ = 5.39 and stable energy dissipation up to 4.06% drift, and the gypsum system showed abrupt strength degradation and was considered seismically inadequate.
What to keep in mind
The study is based on a specific experimental dataset and on the modeling assumptions used in SAP2000. The abstract does not describe other limitations beyond this scope.
Key points
- A single-strut macro-model was developed for lightweight masonry-infilled reinforced concrete frames.
- The model was calibrated to full-scale tests for hollow clay brick, gypsum block, and autoclaved lightweight concrete infills.
- Predicted lateral capacity and initial stiffness were both within 10% error for all systems.
- Hollow clay brick infills greatly increased stiffness but showed brittle failure.
- Autoclaved lightweight concrete panels had the best ductility and stable energy dissipation among the three systems.
Disclosure
- Research title:
- Single-strut model predicts seismic behavior of lightweight infilled RC frames
- Authors:
- Gehad Abou El-fotuh, Walid A. Attia, M. S. El-Feky
- Institutions:
- Cairo University, Cairo University, Heliopolis University, Higher Institute of Engineering, National Research Centre
- Publication date:
- 2026-01-27
- OpenAlex record:
- View
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