【作者】 杨逸帆； 姜淳； 李培振； 吕西林； 甄文君； 麦慧琳； 区彤； 刘雪兵；

【Author】 YANG Yifan;JIANG Chun;LI Peizhen;Lü Xilin;ZHEN Wenjun;MAI Huilin;OU Tong;LIU Xuebing;State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University;Guangzhou New Central Axis Construction Co.,Ltd.;Guangdong Provincial Architectural Design and Research Institute Group Co.,Ltd.;

【机构】 同济大学土木工程防灾减灾全国重点实验室； 广州新中轴建设有限公司； 广东省建筑设计研究院集团股份有限公司；

【摘要】 为降低自重与用钢量,工程中常采用薄腹板箱形钢梁,但受规范宽厚比限值约束,其塑性发展与局部屈曲常被保守控制。本文以广州足球公园屋盖径向箱形梁为原型,采用不同腹板厚度的1∶2缩尺模型,在恒定轴力作用下开展轴力—双向弯曲(N-Mx-My)单调加载试验,系统考察设置纵向加劲肋对薄壁箱梁屈曲演化、承载力与塑性转动能力的影响。结果表明:纵向加劲肋可显著推迟腹板局部屈曲、提高截面塑性参与度与极限承载力,并明显增大塑性转动能力;在满足合理构造与焊接质量的前提下,部分名义宽厚比对应的规范等级(如按规范计算为S3的试件)在试验中呈现接近S1的塑性表现,显示现行限值在此类工况下具有一定保守性。研究证明该类构件用于工程具有足够安全储备,并为薄壁箱形钢梁在双向压弯作用下的加劲设计与宽厚比限值修订提供试验依据与参考。更多还原

【Abstract】 To reduce self-weight and steel consumption,thin-webbed box-section steel beams are commonly employed in engineering practice.However,constrained by the width-to-thickness ratio limits specified in codes,their plastic zone development and local buckling are often conservatively controlled.Taking the radial box-section beams from the roof structure of Guangzhou Football Park as the prototype,this study conducts monotonic loading tests under combined biaxial bending and compression(N-Mx-My) with constant axial force,using 1:2 scaled models with different web thicknesses.The investigation systematically examines the effects of longitudinal stiffeners on the buckling evolution,bearing capacity,and plastic rotation capacity of thin-walled box beams.The results indicate that longitudinal stiffeners can significantly delay web local buckling,enhance the participation of cross-sectional plasticity and ultimate bearing capacity,and notably increase plastic rotation capacity.Under the premise of satisfying reasonable detailing and welding quality,some specimens with nominal width-to-thickness ratios corresponding to certain code classifications(e.g.,specimens calculated as S3 according to code provisions) exhibit plastic performance approaching S1 in tests,demonstrating that the current limits are conservative to some extent under such loading conditions.The research confirms that this type of structural member possesses sufficient safety reserve for engineering applications,and provides experimental evidence and reference for the stiffening design and revision of width-to-thickness ratio limits for thin-walled box-section steel beams under combined biaxial bending and compression.更多还原