钢框架焊接节点损伤破坏行为分析

ANALYSIS ON DAMAGE AND FAILURE BEHAVIOR OF STEEL FRAME WELDED CONNECTIONS

为了正确地评价损伤累积效应对结构的影响并准确的预测结构的破坏形态,采用一批在不同循环加载制度下、构造形式不同的钢框架焊接节点试验,深入分析节点损伤破坏的因素和分类。计算试验中所有节点的累积滞回能、最大变形、最大荷载、屈服位移和屈服荷载,从而根据这些基本参数计算每个节点10种损伤指数的发展趋势,比较损伤模型对于节点损伤退化性能描述,验证并探讨不同损伤模型反应破坏模态以及对结构破坏预测的准确性。试验以及分析结果表明:加载制度对破坏模态有较大影响,对于大幅值加载试件,更易发生逐步退化破坏,而小幅值加载的试件,易发生突然破坏;不同损伤模型具有应用的局限性并且参数组合形式对其损伤指数分布影响较大;以变形为参数的模型也能够较好的表现破坏发展趋势并且通过调整参数,与同时考虑能量的模型分布相近,但其形式更为简单并且只与当前量有关,不需要积分计算,在程序中容易实现,为下一步嵌入程序选取模型提供重要的依据,为今后的工程应用提供有力的工具。

In order to evaluate the effect of damage on buildings and predict the failure forms of structures,a series of tests with different configurations were carried out subjected to various cyclic loading patterns.Typical failure modes and probable damage reasons were discussed in depth.Cumulative hysteretic energy,maximum deformation,maximum load,yield displacement and yield load were calculated for all connections.Then,the various index models were summarized and applied in all the tests,and the damage developmental curves of ten damage indices for each connection were obtained based on these basic parameters.Finally,the prediction and evaluation capacity of various damage models were compared for describing the degraded performance and failure modes.The tests and analysis results show that： The loading history significantly affected the distributive shapes of the damage indices.For ＂large amplitude＂ loading,specimens indicated a progressive failure while a sudden failure for ＂small amplitude＂.Different damage indices have their own scope of application.The selected parameters of the damage indices have great effect on the degradation curves.The model with only displacement variable was recommended,which is easy to be formulated and embedded in application program.