薄柔截面构件屈曲铰及钢框架破坏机构分析

Buckling hinge of non-plastic section members and analysis of failure mechanism of steel frames

对H形薄柔截面构件组成的钢框架结构的极限承载性能及变形性能进行研究。首先对H形薄柔截面钢构件的破坏机制、承载能力、变形及耗能能力等特性进行总结,表明薄柔截面构件延性虽弱,在抗震设计中仍可以被用于耗散能量。针对薄柔截面构件的承载和变形特性,阐述屈曲铰的特征和实现条件。通过引入屈曲铰,对薄柔截面构件钢框架的非线性发展过程进行数值分析。分析结果表明,由"弱延性"构件组成的超静定框架可以实现非线性变形发展条件下的内力重分布,并使框架结构表现出一定的延性。基于结构的最终破坏机构模型,对薄柔构件利用屈曲铰模型,采用极限状态分析法预测框架结构的极限承载能力,并通过2个框架试验验证该方法的可行性。

The ultimate performance and deformability of frames composed of H-shaped non-plastic sectional steel members （NP member） were investigated. Firstly, the failure mechanism, resistance, deformability and energy dissipation capacity of NP members were summarized through experimental studies, which indicate that NP members carl be employed as energy dissipation components in seismic areas despite their limited ductility. Subsequently, a concept named ＇ buckling hinge＇ reflecting the features of NP members along with the requirements for realizing buckling hinges were put forward. Furthermore, by adopting the buckling hinge model, non-linear performance of NP frames was numerically simulated. It is found that with the redistribution process of internal forces, certain degree of stable deformability of statically indeterminate NP frames can be expected even though the individual NP member possesses limited ductility. Finally, based on the ultimate failure mechanism model of steel frames and buckling hinge model of NP members, the ultimate resistance of low rise frames can be predicted through ultimate analysis method with satisfactory accuracy, which was verified by two series of frame tests.