方矩管装配式防屈曲支撑设计理论与试验研究

发布时间：2018-08-16 14:07

【摘要】：装配式防屈曲支撑是一种新型防屈曲支撑,其外围约束构件由多个部件通过高强螺栓拼装组成。如方矩管装配式防屈曲支撑,其外围约束构件就是由两个带有外伸板的方矩管通过高强螺栓紧扣连接而成。装配式防屈曲支撑的加工精度高,现场组装方便,且震后易更换内核,支撑外围构件可重复使用。本文首先对一简化的防屈曲支撑进行了精细有限元分析,对内核构件与外围构件之间接触关系的形成与发展、内核构件波形变化、挤压力分布形式以及外围构件应力水平等进行了研究;考察了内核构件初始缺陷形式、外围构件初始缺陷幅值、内外围之间间隙、外围构件强度与刚度、内核构件长度、内核构件宽厚比及厚度等参数对支撑受力性能的影响。而后以内核外伸的铰接防屈曲支撑为研究对象,对内核发生单波整体变形和内核发生多波屈曲变形时支撑的受力状态进行了深入分析,通过理论推导求解出内核外伸段上最不利弯矩、内核挤压力、外围约束构件上的弯矩分布等。最后基于防屈曲支撑各组成部件的受力特点,建立了外围约束构件设计准则和内核加强段设计准则,完善了传统铰接整体约束型防屈曲支撑的设计理论。相应的理论推导假定及推导结果均通过了数值手段加以验证,此外还对支撑进行了参数分析,研究了9个设计参数对内核挤压力及外围构件受力的影响。因螺栓的离散布置使得装配式防屈曲支撑外围刚度需要一定程度折减,本文采用理论推导及数值验证手段研究了方矩管装配式防屈曲支撑外围约束刚度的取值方法;而后在考虑螺栓离散性对外围约束刚度的折减影响和螺栓间板件局部受力的影响后,提出了一套适用于方矩管装配式防屈曲支撑的设计方法,并设计支撑算例数值验证了设计理论的可行性。最后对方矩管装配式防屈曲支撑螺栓设计理论进行研究,给出了适用的螺栓设计方法。对方矩管装配式防屈曲支撑进行数值分析,研究各设计参数对支撑承载性能的影响,考察了支撑可能存在的破坏形式及影响因素;同时也研究了不同端部构造措施对支撑性能的影响,考察了各构造形式的优劣性。最后,本文对方矩管装配式防屈曲支撑进行了试验研究,验证了本文提出设计理论的安全性和可靠性。试验结果也检验了各类防屈曲支撑构造细节的合理性,为其工程应用提供了充分可靠的依据。
[Abstract]:Prefabricated buckling bracing is a new type of buckling bracing, and its peripheral restrained member is composed of several parts assembled by high strength bolts. For example, the external restraint member of square moment tube assembly buckling bracing is made up of two square moment tubes with outstretched plate which are fastened by high strength bolts. The fabricated anti-buckling brace has the advantages of high machining precision, convenient field assembly, easy replacement of the core after the earthquake, and repeatable use of the supporting peripheral components. In this paper, a simplified anti-buckling bracing is analyzed by fine finite element method. The formation and development of the contact relationship between the kernel component and the peripheral member, and the variation of the core component waveform are discussed. The distribution of extrusion force and the stress level of peripheral members are studied, and the initial defect form, the initial defect amplitude, the gap between inner and outer girth, the strength and stiffness of outer member, the length of kernel member are investigated. The influence of the width to thickness ratio and thickness of the core member on the mechanical performance of the support. Then taking the hinge buckling bracing of the kernel extension as the research object, the stress state of the bracing with single wave integral deformation and multi-wave buckling deformation is analyzed. Through theoretical derivation, the most unfavorable bending moment on the extension section of the inner core, the extrusion force of the core and the distribution of bending moment on the peripheral restrained members are obtained. Finally, based on the mechanical characteristics of the components of buckle-resistant braces, the design criteria of peripheral restrained members and core stiffeners are established, and the design theory of traditional hinged integral-constrained buckle-resistant braces is improved. The corresponding theoretical derivation assumptions and results are verified by numerical means. In addition, the parameters of the braces are analyzed, and the effects of nine design parameters on the core extrusion force and the forces on the peripheral members are studied. Due to the discrete arrangement of bolts, the external stiffness of prefabricated anti-buckling braces needs to be reduced to a certain extent. In this paper, the method of determining the external restraint stiffness of square moment tube fabricated buckle-proof braces is studied by theoretical derivation and numerical verification. After considering the effect of bolt dispersion on the external restraint stiffness and the effect of the local force on the plate between bolts, a design method is proposed for the square moment tube assembly buckling braces. The feasibility of the design theory is verified by a numerical example of design support. Finally, the design theory of square moment pipe assembly buckling supporting bolt is studied, and the suitable bolt design method is given. The influence of design parameters on the bearing capacity of the braces is analyzed numerically, and the possible failure forms and influencing factors of the braces are investigated. At the same time, the influence of different end construction measures on the support performance is also studied, and the merits and demerits of each structural form are investigated. Finally, the experimental study of square moment tube fabricated buckling braces is carried out, which verifies the safety and reliability of the design theory proposed in this paper. The test results also verify the rationality of the structural details of various buckling braces and provide a sufficient and reliable basis for its engineering application.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU398.9

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