蜂窝梁的稳定性能研究进展

对蜂窝梁破坏模式的研究表明,失稳是其结构性能失效的重要破坏模式。为此,在回顾蜂窝梁结构特性研究的基础上,总结归纳了蜂窝梁失稳的3种主要模式：整体弯扭失稳、梁墩屈曲、畸变屈曲。结合国内外近30多年来对蜂窝梁稳定性的试验研究成果,对影响蜂窝梁稳定性的主要因素进行分析。采用蒙特卡洛法得到纯弯简支蜂窝梁弯扭失稳临界荷载的概率分布和影响因子的敏感度。将部分具有代表性的试验成果与欧洲规范EN 1993-1-1计算结果进行对比,根据中国规范GB 50068—2001《建筑结构可靠度设计统一标准》提供的抗力分项系数,计算了不同荷载组合下蜂窝梁整体弯扭失稳临界荷载的可靠度指标,为国内规范的制订提供依据。最后,总结了当前蜂窝梁稳定性研究中存在的不足,指明了进一步研究的方向。

Advances on stability performance of castellated beams

Studies on failures of castellated beams have identified instability as a critical one. After reviewing the existing investigations, the buckling modes of castellated beams could be summarized into three categories: lateral-torsional buckling, web post buckling and distortional buckling. Based on the studies on the stability of castellated beams published in recent 30 years, the main factors that influence the stability of castellated beams were investigated. The probability distribution and sensitivity of the influencing factors of simply supported castellated beams subjected to pure bending were obtained by using the Monte Carlo method. Furthermore, part of the representative test results were compared with the European code EN 1993-1-1 predictions. Based on the partial safety factor for resistance in Chinese specification GB 50068—2001 ‘Unified standard for reliability design of building structures’, a calculation of reliability index of castellated beams experiencing lateral-torsional buckling under various loading conditions was conducted, which formed basis on the development of domestic specification on castellated beams. Finally, this paper summarized the shortcomings of the current research on the stability of castellated beams, and further research direction was pointed out.