Numerical Study on the Shear Capacity-Curvature Ductility Relationship of High Strength Reinforced Concrete Beams under Different Failure Modes Using ABAQUS

Studying shear capacity in reinforced concrete beams is vital for structural safety and integrity. Preventing sudden shear failure is essential to avoid catastrophic collapses and ensure reliable construction performance. ABAQUS is vital for the thorough analysis of concrete specimens, offering deeper insights into their behavior under different experimental conditions. This paper explored the correlation between shear capacity and curvature ductility in high-strength reinforced concrete cantilever beams subjected to monotonic loading, involving tests on six cantilever beams with cross sections measuring 200 mm by 300 mm. The study examined how span-to-effective depth ratios ("a/d") and stirrup spacing influence beam behavior at the plastic hinge under various failure modes: flexural, shear, and combined. The specimens were categorized into two groups, with each group comprising 3 beams and 3 values for each variable. In the first test group, as the a/d ratio increased from 750 to 850 and then to 1150 mm, shear capacity increased by 99.3% and 16.3%, while curvature ductility improved by 45.5% and 29.7%. The failure modes included shear, combined, and flexural, indicating a direct yet non-linear relationship between curvature ductility and shear capacity. Increasing stirrup spacing from 100 to 150 and then to 300 resulted in a 37.3% and 59.2% decrease in shear capacity and an 18% and 58.8% reduction in curvature ductility. This demonstrates an inverse non-linear relationship and a shift in failure mode from flexural to combined and then to shear.