【作者】 李菁；

【导师】 王雪亮；

【作者基本信息】 武汉理工大学 ， 土木工程， 2022， 硕士

【摘要】 连接节点的力学性能影响到结构体系的承载力和整体稳定性,对装配式木框架结构的影响更为显著。胶合木框架结构的节点通常采用钢填板-螺栓连接,研究表明该类连接节点延性性能较差且具有较低的抗弯承载力,地震作用下会导致节点过早的失效。为改善节点的受力性能,避免节点的脆性破坏,本文在钢板-螺栓连接节点的基础上,提出了两种新型连接节点即槽式削弱型钢填板-螺栓梁柱连接节点与限位弧形软钢-钢插板柱脚连接节点,通过理论分析和有限元模拟对其破坏机理和力学性能进行了研究。在此基础上,将两种新型节点应用于胶合木框架结构形成新型延性结构体系,并对其抗震性能进行了研究。主要研究工作和结论如下:(1)通过有限元软件ABAQUS对槽式削弱型钢填板-螺栓连接节点的滞回特性和耗能能力进行分析,结果表明,槽式削弱型钢填板螺栓连接节点是一种构造合理,具有良好耗能作用的连接形式,与普通钢填板-螺栓节点对比,其延性、承载力及耗能能力均有所提升。(2)设计了一种限位弧形软钢-钢插板柱脚连接节点,建立了普通钢插板柱脚连接的胶合木柱与新型柱脚连接的胶合木柱的精细化有限元模型,对其单调和往复荷载作用下的力学性能进行了分析。结果表明,新型限位弧形软钢-钢插板柱脚连接节点改变了普通钢插板柱脚连接节点的受力机理和破坏模式,与普通钢插板柱脚连接节点相比,新型柱脚节点的延性有明显提升,节点承载力较比普通柱脚节点提升了25.3%;往复荷载作用下,该节点具有良好的滞回特性和稳定的耗能能力,能够避免或延缓木材出现过早的劈裂而引起的结构破坏。(3)考虑到胶合木框架结构中节点的半刚性特点及其对整体结构力学性能的重要影响,将梁柱节点及新型柱脚节点简化为半刚性连接,运用卡氏定理推导出新型胶合木框架结构在水平荷载作用下的抗侧刚度理论公式。(4)运用有限元软件ANSYS对刚接框架、普通半刚接框架和新型连接框架进行地震时程分析,结果表明,采用新型连接的胶合木框架结构具有良好的抗震性能,与普通连接的胶合木框架相比,显著降低了各楼层的峰值加速度,且随着地震波峰值加速度的增大,顶层加速度降幅更明显,最大峰值加速度降幅达到了38.27%。但由于新型连接框架节点的连接刚度较小,其层间侧移较大,不宜单独作为受力体系,应根据实际情况,在延性框架体系中增设支撑或剪力墙等措施,使木结构延性体系的层间侧移和顶层位移得到有效的控制。更多还原

【Abstract】 The mechanical properties of the joints affect the bearing capacity and global stability of the structural system,especially the fabricated wood frame structure.The joints of GLT frame structure are usually connected by bolted joints with slotted-in steel plate.The research shows that this kind of joints have poor ductility and low bending capacity,which will lead to premature failure under earthquake.To improve the mechanical properties of the joint and avoid its brittle failure,based on the slotted-in steel plates,this paper proposes two new-type of connection joints which are weakened slotted-in steel plate connection and arc mild steel of limit column base with slotted-in steel plate connection.The failure mechanism and mechanical properties are studied by theoretical analysis and finite element simulation.On this basis,the two types of joints are applied to GLT frame to form a ductile structure whose seismic performance is studied.The main conclusions are as follows:(1)By the finite element software ABAQUS,the hysteretic characteristics and energy dissipation capacity of the weakened slotted-in steel plate connection are analyzed.The results show that this kind of connection has a reasonable configuration and good energy dissipation.Compared with the common connection,its bearing capacity and energy dissipation capacity are improved.(2)An arc mild steel of limited column base with slotted-in steel plate connection is designed,and finite element models of GLT column connected by common connection and new connection are established to analyze the mechanical performance under monotonic and reciprocating loads.The results show that the mechanical mechanism and failure mode of the new column base connection are changed.Compared with the common column base connection,the ductility of the new joint is significantly improved,and the bearing capacity of the new joint is25.3% higher than that of the common joint.Under reciprocating load,the joint has good hysteretic characteristics and energy dissipation capacity,which can avoid or delay the structural damage caused by premature splitting of wood.(3)Considering the important influence of the semi-rigid characteristics of the joints on the performance of GLT structure,the beam-column joints and the new column base joint are simplified as semi-rigid connections to deduce the theoretical formula of lateral stiffness of the new GLT structure using the Castigliano’s Theorem.(4)The nonlinear time-history analysis of GLT frames with rigid connection,common semi-rigid connection and new connection under earthquake is carried out using the finite element software ANSYS.The results show that the glued wood frame structure with new connection has good seismic performance.Compared with the common semi-rigid glulam frame,the peak acceleration of each floor is significantly reduced,and the decline of top floor acceleration is more obvious with the increase of seismic wave peak acceleration,The maximum peak acceleration decreased by 38.27%.However,due to the small connection stiffness of the new frame joint and its large inter-story drift,it is not suitable to be used as a stress system alone.According to the actual situation,measures such as m braces or shear wall should be added in the ductile frame system to effectively control the inter-story lateral drift and top floor displacement of the wood structure ductile system.更多还原