【作者】 刘鹏远；

【导师】 滕军； 李祚华；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2019， 博士

【摘要】 主次结构体系是由提供主要承重能力及抗侧能力的主结构与仅承担自身荷载的次结构组成,并能高效协同工作的一种新型结构体系。新型主次结构中构件类别多、功能属性复杂,其力学特性、屈服失效机理及失效模式优化等方面与常规结构体系存在显著差异,常规结构的抗震设计概念对其并不完全适用,限制了该新型结构体系的推广应用。因此,有必要在分析该结构体系受力特点的基础上,确定合理地震失效模式,并给出实现合理地震失效模式的主动调控方法及手段,为主次结构体系抗震性能设计提供理论方法和依据。本文从主次结构的受力特点、刚度形成机制、地震失效模式、抗震概念、支撑优化设计及结构失效模式调控方法等方面展开研究。论文主要研究工作如下:在受力特点方面,考虑主次结构中构件类别与功能属性的差异,从结构构成及传力角度出发,探讨并给出了主次结构力学概念。通过数值模拟研究了主次结构的受力特点及变形规律,明确了支撑布置形式、连接形式以及次柱连接形式等因素对主次结构受力及变形的影响,揭示了主次结构显著的二级受力特点及次结构内力的周期性与可复制性。在刚度形成机制方面,通过变参数分析,探讨了影响主次结构抗侧刚度的主要力学参数,揭示了主次结构刚度形成机制,并推导给出了主次结构模块抗弯、抗剪刚度计算方法及结构侧向位移简化计算方法。基于主次结构力学概念及刚度形成机制,规划了主次结构的合理地震失效模式。通过对典型主次结构模型进行弹塑性分析,重点关注构件截面参数变化对构件屈服顺序的影响规律,验证并明确了主次结构的合理构件屈服顺序。研究了外筒构件塑性分布特征及内外筒间内力分配过程,阐明了内外筒内力重分配特性及结构多道抗震防线,进而提出支撑的退出工作是实现结构多道抗震防线的关键。研究了各类构件参数变化对抗侧刚度及耗能的影响,确立了结构抗侧刚度关键构件和塑性耗能主要构件,给出了主次结构体系的抗震概念。基于主次结构合理地震失效模式,确立了实现合理失效模式的拉压可退化支撑优化原则,并基于局部部件屈曲原理,提出了退化可控支撑设计概念。通过分析退化可控支撑的受力机理,给出了退化可控支撑的简化本构模型。基于本设计概念明确了一种退化可控支撑构造形式,并通过拟静力试验研究,论证了退化可控支撑核心板厚度、初始挠度及材料等参数对支撑承载力退化特性及耗能能力的影响,验证了退化可控支撑构造的合理性,揭示了退化可控支撑的破坏机理及其力学特性可调控机制。基于退化可控支撑力学特性的可调控特点,通过动力弹塑性分析,阐明了退化可控支撑对结构塑性发展过程、结构地震动输入及关键构件破坏模式的影响,揭示了基于退化可控支撑的主次结构地震失效模式调控机理。通过主动调整退化可控支撑屈曲临界荷载及屈曲后承载力,分析并明确了其参数调整对主次结构失效模式的调节规律与效果。最终,以实现主次结构合理地震失效模式为目标,提出了基于退化可控支撑的主次结构地震失效模式调控方法,并通过典型工程应用验证了本文失效模式调控方法的有效性,为主次结构大震设计及合理地震失效模式的调控实现提供了方法和依据。更多还原

【Abstract】 The primary-secondary structural system is a new structural system composed of the primary structure which provides the main bearing capacity and lateral resistance and the secondary structure which only bears its own load,and the primary structure and the secondary structure can work together efficiently.The components in the new primarysecondary structure have the characteristics of multiple categories and complex functional attributes,which leads to significant differences between the mechanical properties,yield failure mechanism and failure mode optimization of the primary-secondary structure and the conventional structure.The seismic design concept of the conventional structure is not fully applicable to the primary-secondary structure,which limits the popularization and application of this new structure system.Therefore,it is necessary to determine the reasonable seismic failure mode based on the analysis of the mechanical characteristics of this structural system and provide active regulation methods and means to achieve the reasonable seismic failure mode,so as to provide theoretical methods and basis for the seismic performance design of the primary-secondary structure.This paper conducts research from the aspects of mechanical characteristics,stiffness formation mechanism,seismic failure mode,concept of structural seismic design,brace optimization design and seismic failure mode regulation methods of primarysecondary structures.The main research work of this paper is as follows:In the aspect of mechanical characteristics,considering the differences in the types and functional attributes of components in primary-secondary structures,the mechanical concepts of primary-secondary structures were discussed from the perspective of structure composition and force transmission.Through the numerical simulation,the mechanical characteristics and deformation laws of the primary-secondary structures were studied.The influences of brace arrangements,connection forms and secondary column connections on the internal force and deformation of primary-secondary structures were clarified.The significant two-level mechanical characteristics of primarysecondary structure and the periodicity and reproducibility of internal forces of the secondary structure were revealed.In terms of stiffness formation mechanism,through the analysis of variable parameters,the main mechanical parameters affecting the lateral stiffness of primary-secondary structures were discussed,the mechanism of stiffness formation of primary and secondary structures was revealed,and the calculation method of bending and shear stiffness of primary-secondary structural modules and simplified calculation method of structural lateral displacement were deduced.Based on the mechanical concept and stiffness formation mechanism of the primarysecondary structure,a reasonable seismic failure mode for the primary-secondary structure was planned.Through elastoplastic analysis of typical primary-secondary structure models,the paper focuses on the influence of the change of component section parameters on the yield order,verified and clarified the reasonable component yield order of primary-secondary structure.This paper studied the plastic distribution characteristics of the outer tube components and the internal force distribution process between the inner and outer tubes,clarified the internal force redistribution characteristics of the inner and outer tubes and the multiple seismic fortification lines of the structure,and put forward that the key to realize multiple seismic fortification lines is the degradation of brace.The influences of various component parameter changes on lateral stiffness and energy consumption were studied.The key structural lateral stiffness components and the main plastic energy dissipation components were established,and the seismic concept of primary-secondary structural systems was proposed.Based on the reasonable seismic failure mode of primary-secondary structures,the optimization principle of tension-compression degradable brace was established,and the design concept of degradation controllable brace was proposed based on the buckling principle of local components.By analyzing the force mechanism of the degradation controllable brace,a simplified constitutive model of degradation controllable brace was proposed.Based on this design concept,a structure form of degradation controllable brace was developed.The effects of parameters such as the thickness,initial deflection,and material of the degradation controllable brace core plate on the degradation characteristics and energy dissipation capacity of the brace were demonstrated through pseudo-static test research.The rationality of the degradation controllable brace structure was verified,and the failure mechanism and the regulation mechanism of mechanical properties of the degradation controllable brace were revealed.Based on the controllable characteristics of the mechanical properties of the degradation controllable brace,through dynamic elastoplastic analysis,the effects of the degradation controllable brace on the structural plasticity development process,structural ground motion input,and key component failure modes were clarified,and failure mode regulation mechanism of the primary-secondary structure was revealed.By actively adjusting the buckling critical load and the post-buckling bearing capacity of the degradation controllable brace,the regulation and effects of the parameter adjustment on the primary-secondary structural seismic failure modes were analyzed and clarified.Finally,in order to achieve the reasonable seismic failure mode of primary secondary structures,seismic failure mode regulation method of primary-secondary structure based on degradation controllable brace was proposed.The effectiveness of the failure mode regulation method was verified by the typical engineering application,which provides the method and basis for the seismic design and realization of reasonable failure mode of primary-secondary structure.更多还原