【作者】 章东强；

【导师】 蒋沧如；

【作者基本信息】 武汉理工大学 ， 结构工程， 2009， 博士

【摘要】 轻钢结构体系具有强度高、重量轻、抗震性能好、保温隔热性好,耐久性好、用钢量少、造价低、可标准化生产、施工方便的特点,近10年来在我国得到快速的发展。本文针对一种新型的轻钢龙骨体系-IBS (Integra Building System)结构体系的构件、墙体、整体模型进行试验研究,分析了该体系构件的承载力、变形和破坏模式、动力特性等,为制订该体系的设计和施工规范提供依据。通过IBS结构体系13个桁片梁试验研究其承载力、破坏模态、变形、抗弯刚度以及平面外抗弯刚度等力学性能,结果表明桁片梁的极限承载力和刚度较小,不适宜单独作为受力构件,采用大截面的上弦杆可以提高梁的整体稳定承载力。建立合理的桁片梁有限元分析模型,通过有限元分析影响桁片梁承载力和跨中最大挠度的因素,桁架梁极限承载力主要由上弦管截面决定,上弦管截面越大,梁的极限承载力和刚度越大；V型连接件倒置(尖角向上)会使桁架梁的承载力变小,大型号的v型连接件可增大桁架梁的极限承载力,减少梁跨中挠度,提高梁的抗弯刚度。通过6个试件轴向荷载作用下极限承载力试验,研究桁片和四方柱轴心极限承载力的影响因素和破坏形式,表明IBS结构体系中的单桁片柱和四方柱的轴压极限承载力较低,不建议其作为单独的轴向受力构件。完成了9个梁柱节点试件的承载力试验,分析节点在分级荷载作用下的变形和应变变化规律,获到各试件的极限承载力,提出了提高梁柱节点刚性的具体措施。利用通用有限元软件建立了IBS结构体系梁柱节点的有限元计算模型,比较了试件测试数据和有限元分析结果,计算给出了三种典型IBS结构体系梁柱节点的M-0特征曲线。通过5个竖向荷载作用墙体试件和1O个水平荷载作用墙体试件对IBS结构体系龙骨墙体和复合墙体的竖向承载能力、水平承载能力及其变形和破坏规律进行详细的研究。试验表明：无蒙皮墙体竖向承载力低,增加横撑和斜撑能提高其承载力,但增加了用钢量；有蒙皮墙体的竖向承载力得到很大的提高,整体变形小,材料的强度得到较充分的发挥,多呈强度破坏；无蒙皮墙体水平荷载主要由斜拉钢带承担,洞口对墙体的抗侧力影响较大,有蒙皮墙体的抗侧能力较高,有蒙皮墙体具有较好的整体性,侧向力作用下不再呈现剪切形变形。运用有限元软件建立IBS结构体系龙骨墙体和复合墙体的有限元模型,通过大量的有限元数值计算研究了蒙皮对复合墙体竖向承载力的影响,对复合墙体竖向承载力影响最大的是蒙皮,其次是墙体的高度、厚度和横撑的数量；提出了IBS结构体系墙体竖向承载力计算方法。对抗侧力墙体的有限元数值研究表明：竹胶板蒙皮墙体比OSB板蒙皮墙体和纸面石膏蒙皮板墙体具有更高的抗侧能力；随着蒙皮厚度的增加,复合墙体的水平承载力有所提高,但趋于不显著；蒙皮的数量对水平承载力有较大影响,斜拉钢带横截面积的增加也能提高墙体的水平承载力,但提高不明显；随着墙体内桁片柱间距的减小,墙体水平承载能力有较大的提高。根据影响复合墙体抗剪强度和抗剪刚度的主要因素,在分析一般轻钢龙骨复合墙体的抗剪强度和抗剪刚度简化计算方法的基础上,建立了IBS结构体系复合墙体的抗剪强度和抗剪刚度计算公式。利用1：1的足尺模型,对一个两层无比钢结构房屋进行了振动台试验与动力分析。测试了结构的动力特性以及结构在不同输入波激励下的动力反应。运用有限元方法对该模型结构进行了理论分析,计算结果能很好地与实测结果相吻合,为IBS结构体系的抗震设计提供相关参数与理论依据。更多还原

【Abstract】 Lightweght steel structures are higher strength and durability, superior aseismic performance lightweight for easy handing and lower costs, manufactured to exacting standards to produce pre cut lengths and angles, also able to withstand most environmental conditions that can qualify for lower fire insurance premiums. In recent 10 years these systems are developed rapidely in China. In this paper, the Integra building system (IBS) which is a web light gauge steel system is introduced. The bearing capacity, deflection, failure modes and dynamic performance of its member, shear wall and structure system are researched based on experiments for its codes of design and construction.The bearing capacity, failure modes, deformation, bend stiffness in plane and out plane of floor joist are tested by 13 floor joist specimens. The results suggest that a single foor joist is not suitable for bearing loads for its lower ultimate bearing capacity and stiffness out plane, the stabiliy bearing capacity can be improved with larger cross section of up-tube of joist floor. Compare with test results the finite element analysis (FEA) models of joist floor are rational. Parameters which have effect on bearing capacity and deflection of mid-span are investigated by FEA. Corss section of up-tube of floor joist has most effect on its ultimate bearing capacity. With larger cross section of up-tube, the ultimate bearing capacity and stiffness are higher. Upside-down clips in members can decrease ultimate bearing capacity. Large clips can improve ultimate bearing capacity, reduce deflection of mid-span and increase its bending stiffness.The ultimate bearing capacity and failure modes of studs and box columns are studied with 6 spcimens which bear axis press loads. The data suggest that its ultimate bearing capacity is lower, its can not use alone as structure member.9 connnection specimens (3 types) have been studied for the deformation, strain and ultimate bearing capacity under each level load. Based on the result, detail means for improving stiffness of connections are bring forward. The connections are modeled in finite element analysis software; the results of FEA are closed to data of experiment for specimens. Three type M-θcurves are given for IBS connections.Vertical bearing capacity, lateral bearing capacity, deformation and failure modes of IBS wall are researched through 5 specimen which bear veritical load and 10 ones which bear lateral load. Experiment result shows that bearing capacity of these walls without sheathing is lower. More horizontal and "X" bracing, more bearing capacity is, but more steel need. But veritical bearing capacity of IBS wall with seathing is higer, deformation is less. Intensity of steel is brought into sufficient play, and failure of wall with sheathing is strength one. Lateral load is beared mainly by diagonal tension straps; window and door opening in the wall have serious effect on its bearing capacity. The wall with seathing has suporier lateral performance and structure integrity, and its deformation is not more shear type under lateral loads.Parameters effect on veritical bearing capacity of IBS wall with sheathing and without seathing have been instigated by FEA, the most important factor effect on veritical bearing capacity of wall is sheathing, next is high, thickness of wall and number of horizontal bracing. Design method of veritical bearing capacity is brought forward. The result of FEA shows that lateral capacity of wall with bamboo glue panel is higher than one of wall with OSB panel and gypsum panel, and more thickness, number of sheathing, cross section of diagonal tension steel strap and less span between studs in wall, more lateral capacity the wall has.Based on study of mainly factors effect on shear strength and shear stiffness and its simplified formulas for general light gauge steel structure, these formulas for IBS wall are put forward.Shaking table test and dynamic analysis of a full size two-layer model is performed. Dynamic characteristic of the model and dynamic response under various wave excitations input are studied. Finite element method is used for dynamic analysis of this model, these results are close and can provide relative data and reference.更多还原