The College of Engineering at the University of Baghdad hosted the public defense of Master’s student Ali Mohammed Abdulridha from the Civil Engineering Department for his thesis titled:
“Experimental and Numerical Investigation of Concrete-Filled Steel Tube Beams with Transverse Openings.”
The defense took place on Thursday, February 27, 2025, in Dr. Khalid Shaker Hall, under the supervision of Asst. Prof. Dr. Salah R. Al Zaidee.
Research Overview
The study focused on an experimental and numerical investigation of the effects of circular transverse openings on the behavior of simply supported concrete-filled steel tube (CFST) beams. Three openings, each with a diameter equal to 40% of the beam depth, were analyzed. A parametric study was later conducted using Abaqus to explore the impact of opening size and location.
Key Findings
- Concrete infill significantly enhances structural performance, increasing:
- Load-carrying capacity by up to 224.5%
- Ductility by 187.1%
- Energy absorption by 1300%
- Transverse openings reduce structural strength, with CFST beams experiencing:
- Up to 18.6% reduction in load-carrying capacity (compared to only 3.77% in hollow steel tube (HST) beams)
- Up to 20% decrease in ductility (compared to 2.54% in HST beams)
- Up to 30.7% reduction in energy absorption (compared to 14.1% in HST beams)
- Parametric Study Insights:
- Larger diameter-to-depth (D/d) ratios significantly reduce CFST beam strength.
- Spacing-to-depth (S/d) ratios show that while CFST beams initially gain strength with increased spacing, excessive spacing leads to a decline. HST beams, however, exhibit notable reductions beyond specific thresholds.
Recommendations for Future Research
The study proposes further investigations into:
- Alternative opening shapes (e.g., elliptical, rectangular) and their effects on structural performance.
- Opening location variations and their influence on beam behavior.
- Dynamic loading conditions (e.g., seismic, impact loads) on CFST beams with openings.
- Additional reinforcement strategies, such as stiffeners or enhanced concrete infill, to mitigate strength loss.
Thesis Outcome
After the scientific discussion and evaluation by the esteemed members of the defense committee, Ali Mohammed Abdulridha was awarded a Master’s degree in Civil Engineering / Structural Engineering.
