Evaluation of web post-buckling in high-strength cellular steel and high-strength concrete composite beams: A numerical study

This study numerically investigates the instability in the web of composite beams subjected to positive moments, using high-strength steel cellular profiles and high-strength concrete. The research was conducted through 360 numerical analyses performed in ABAQUS, varying the size ratio (Do/d), spacing of the cells (P/Do), length of the beams (L), and types of the cross-section. Concrete slabs were not the primary cause of failure, with damages from compression and tension having minimal influence as failures occurred in the steel profile. Longer beams, larger openings, and higher Do/d ratios reduced load capacity, while higher P/Do ratios and thicker profiles improved performance. The horizontal shear values (Vh) were obtained directly from the ABAQUS model and the Steel Design Guide 31 (SD31), which manipulates the global shear obtained from the software to calculate the horizontal shear. The values obtained directly from ABAQUS were consistent. They showed that each model performs better under certain conditions: Ward and Panedpojaman models performed well under intermediate configurations, Grilo excelled in long beams with small openings, and Eurocode 3 is suitable for large openings. This underscores the need to optimize geometric parameters and select appropriate models to ensure efficiency and safety in structural applications with high-strength materials.