摘要
通过对4个足尺比例冷弯薄壁型钢-混凝土组合楼盖的受弯承载力进行单调静载试验研究,分析了压型钢板与冷弯薄壁型钢梁连接的螺钉间距和楼盖梁数量改变对组合楼盖极限承载力的影响及破坏机理。研究表明:在正常使用阶段,组合楼盖具有较高的承载力和较小的变形;减小螺钉间距和增加楼盖梁数量均能够提高组合楼盖的极限承载力。破坏模式主要表现为楼盖梁发生弯扭屈曲的同时,受压区翼缘、卷边及毗邻腹板出现相关屈曲破坏,屈曲波长为相邻螺钉间距;支座附近混凝土与压型钢板为脱离、掀起破坏;集中荷载作用点处楼盖梁为折曲破坏。采用考虑材料、几何和接触非线性ANSYS有限元程序对试验模型的受力性能进行了模拟,非线性有限元计算结果与试验结果吻合较好。在试验研究和有限元分析基础上,提出了组合楼盖的简化计算模型和理论计算方法。
Four full-scale cold-formed steel joists and concrete composite floors were tested under monotone static loads to study the flexural capacity, and the effects to the ultimate bearing capacity and the failure mode of composite floor, when the space between the screws connect the ribs of profiled steel sheet and the joists of cold-formed steel floor was changed or the number of the floor joists was different. The research shows that the bearing capacity is relatively high and the deformation is very small when the composite floor is in service stage, and the ultimate bearing capacity can be improved both by increasing the quantity of floor joists and by reducing the space between screws. The main failure modes are the curing of compression flange, buckling of web with wave length of bucking bing the distance between adjacent screws corresponding to the bending and torsioning deformation of the joists. The separation of concrete away from the profiled steel sheet close to the supports. Distortion damage of floor joists at the position concentrated loads. Considering the material, geometry, and contract nonlinearity, the experimental results were simulated with FEM using program ANSYS, and the nonlinear FEM results agree well with the test results. Finally, on the basis of experimental study and FEM analysis, simplified calculation model and calculation method are proposed.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2010年第7期13-22,共10页
Journal of Building Structures
基金
国家自然科学基金项目(50578013)
教育部高等学校博士学科点专项基金项目(20050710004)
关键词
组合楼盖
冷弯薄壁型钢梁
静力试验
非线性有限元
极限承载力
破坏模式
composite floor
cold-formed steel joist
static test
nonlinear finite element
ultimate bearing capacity
failure mode
