Experimental study on mechanical properties of hybrid-steel castellated beams with hexagonal holes

• Published in: Structures (Oxford) 2025-03, Vol.73, p.108319, Article 108319
• Main Authors: Ning, Qiujun, Chen, Xiangrong, Lu, Xiaosong, Lu, Jiawei
• Format: Article
• Language: English
• Subjects: Hybrid-steel castellated beam; Local stability; Mechanical property; Orthogonal test method; Simplified calculating formula
• ISSN: 2352-0124; 2352-0124
• DOI: 10.1016/j.istruc.2025.108319

In this paper, the orthogonal test method (OTM) is used to conduct the static test of the prototype structure comprising 18 hybrid-steel castellated beams with hexagonal holes. The influence of the height-to-thickness ratio, width-to-thickness ratio, hole-to-height ratio, and upper flange strength on the local stability of castellated beams is analyzed. The key factors affecting the local buckling of hybrid-steel castellated beams are identified. The simplified calculation formula for deflection and strength of hybrid-steel castellated beams with hexagonal holes is derived using the mean value theorem of definite integrals. The analysis results showed that the height-to-thickness ratio and width-to-thickness ratio significantly influence the ultimate load of the castellated beam, while the effect of the hole-height ratio and the strength of the upper flange is relatively minor. With the increased strength of the upper flange of the castellated beam, the ultimate bearing capacity of the beam is also enhanced. However, the compressive flange of the castellated beam is more susceptible to local buckling. The proposed simplified calculation formula for deflection and strength of hybrid-steel castellated beams takes into account the distinctive shape of the castellated beam openings, and which holds significant practical value and aligns well with engineering requirements.