摘要
为了研究空间网架结构螺栓球节点高温下的受力性能,通过18个螺栓球节点试件高温下的受拉试验,得到了不同温度下螺栓球节点试件受拉承载力。试验结果表明:高温下试件破坏截面均位于高强度螺栓螺纹处,温度低于400℃时,试件发生脆性断裂;温度不小于400℃后,试件破坏时的截面颈缩明显,发生延性破坏。随着温度升高,螺栓球节点试件的刚度、极限荷载逐渐降低;温度超过300℃后,节点试件刚度、极限荷载下降很快。根据试验数据拟合得到了螺栓球节点受拉极限荷载折减系数表达式。与已有的高温下高强度螺栓材料的受拉屈服强度和极限强度折减系数相比,螺栓球节点的相应折减系数更低。
In order to study the mechanical behavior of the bolt-sphere joint in the space grid structure under high temperature, the tensile capacity of the bolt-sphere joint was obtained under different temperatures by tension test of 18 bolt-sphere joint. The results show that, destruction section of the bolt-sphere joint occurs in the thread of the high strength bolt at high temperature. The brittle fracture occurs when the temperature is below 400 ℃. The ductile damage occurs and there is an apparent necking cross section when the temperature is equal to or greater than 400 ℃. As the temperature increases, the stiffness and ultimate load of the bolt-sphere joint decrease gradually. When the temperature is greater than 300 ℃, the stiffness and ultimate load of the bolt-sphere joint decrease rapidly. The tensile ultimate load reduction coefficient expression of the bolt-sphere joint was obtained by the experimental data. Compared with the reduction coefficient of tensile yield strength and ultimate strength of high strength bolt in high temperature, the reduction coefficient of the bolt-sphere joint is lower.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第11期55-60,共6页
Journal of Building Structures
基金
国家自然科学基金项目(51378259)
关键词
空间网格结构
螺栓球节点
高温作用
受拉试验
受力性能
space grid structure
bolt-sphere joint
high temperature action
tensile test
mechanical behavior
