草原地区装配式双肢冷弯薄壁型钢房屋受力性能研究

With the improvement of the grassland region of buildings space, environmental protection mobility and other requirements, in view of the policy guidance of national construction industrialization and the advantage of cold-formed thin-walled steel used in low-rise buildings in the grassland region, the fabricated cold-formed thin-walled steel housing was put forward, which adopt a new "non-box type" rigid frame system using double lipped cold-formed thin-walled C steel. Without changing the Inner Mongolian characteristic decoration and building function, a new grassland region fabricated building system was built, which can effectively improve the building’s space utilization, mechanical behavior and durability. The spatial structure and plane rigid frame of the building were selected as the research objects. Through the theoretical analysis, horizontal low cycle loading test and finite element analysis , the failure mode, ultimate bearing capacity and plastic hinge distribution of the building structure under the typical grassland region load were got. The stressed-skin diaphragm of enclosure structure was carried out and the feasibility and requirements of the stressed-skin design were presented by the stressed-skin test and the finite element analysis. Finally, the calculation method of the ultimate bearing capacity of the building structure and the calculation method of the plate group restraint coefficient and the stability coefficient of the plate group under the influence of the pad were given, which gives a reference for the engineering application.

随着草原地区对房屋建筑的空间、环保、迁移性等要求的提高，考虑到国家建筑工业化的政策导向和冷弯薄壁型钢用在低层房屋建筑上的优势，本课题从草原地区装配式冷弯薄壁型钢房屋入手，采用新型双肢冷弯薄壁C型钢构件组成“非盒子式”的刚架体系，在不改变蒙古族特色造型和房屋功能的基础上，构建一种新型的草原地区装配式房屋体系，可以有效提高其使用空间、受力性能和耐久性。选取该类房屋建筑的空间结构和平面刚架作为研究对象，通过理论分析、水平低周往复荷载试验和有限元数值分析该房屋结构在草原地区典型荷载下的破坏模态、极限承载能力及塑性铰分布等力学性能，在风雪耦合作用下的动力稳定性。进行围护结构蒙皮效应分析，通过蒙皮试验和有限元分析提出蒙皮设计的可行性和要求。最终得到该类房屋结构的极限承载力计算方法和垫板影响下C型钢的板组约束系数和板组稳定系数的计算方法，为该类房屋结构的设计与应用提供参考依据。

采用双肢冷弯C型钢构建出一种适应草原地区的新型装配式蒙古包房屋体系。该蒙古包的主要承力骨架是对称的带陶脑的双肢冷弯C型钢门式刚架结构，采用正多边形设计，以陶脑为中心旋转为空间蒙古包结构。. 该蒙古包承重单榀门式刚架稳定承载力高，抗侧性能好。为了提升平面刚架的抗震性能，可适当增大C型钢厚度和柱腹板高度。建议进行抗震设计时，C型钢的厚度不应小于2.5mm，节点板厚度不应小于6mm。在竖向荷载作用下平面刚架均发生对称平面内整体失稳，且都按照先梁柱节点后陶脑节点、先局部屈曲后畸变屈曲的顺序发生破坏，刚架梁呈S形向下挠曲变形，刚架柱均有向外侧移。刚架斜梁坡度越大、高跨比越小，刚架平面内稳定极限承载力越高。. 进行装配式蒙古包房屋部品库优化设计，并开展水平低周往复荷载试验。对称结构设计使得无论是采用何种加载方式，传力路径都是对称发展的，体现出蒙古包良好的承载能力和充足的抗震性能。蒙古包加蒙皮后极限承载力提高了1.3倍，八边形比六边形提高了1.7倍，梁柱节点加强后提高了1.4倍，屋顶坡度影响不大。冷弯型钢蒙古包采用螺栓连接，轻微的螺栓滑移可使结构具有较好的耗能能力。若对承载力有较高要求时，可通过节点增加少量焊缝的方式可提升承载力40%。风雪流固耦合分析得到了蒙古包结构的风荷载体形系数和风致雪荷载分布系数，与现行门刚规范有所差别，给出了雪荷载分布系数取值参考。. 通过数值分析得到蒙古包刚架极限承载力、柱顶破坏位移的经验公式、刚架柱的计算长度修正系数公式和恢复力模型，可用于平面刚架设计和承载力预估。针对梁柱节点和柱脚节点的全螺栓连接构造，推导出节点刚度的理论计算公式。双肢构件中垫板的加入改变了C型钢板组约束条件，通过理论分析给出了双肢构件的双垫板和三垫板构造的板组约束系数计算公式。. 本项目研究开发的新型草原地区房屋建筑，顺应装配式钢结构建筑的发展方向，可为内蒙古地区乡村振兴基础设施建设添砖加瓦。