【作者】 王刚；

【导师】 周方圆；

【作者基本信息】 华中科技大学 ， 建筑与土木工程， 2020， 硕士

【摘要】 装配式建筑是顺应时代发展的重要建造方式之一,它具有建设周期短、施工速度快,环境污染小,节约资源等优点。将预应力技术融入到装配式建筑设计中,能够有效的解决装配式建筑的节点连接问题,从而能够大大的提高装配式建筑的安全性能。基于此,开展预应力装配式节点相关力学性能研究具有重要的实际工程意义及广阔的推广应用前景。由于目前国内预应力装配式节点的研究还处于起步阶段,缺乏完善的设计方法和标准体系,本文在已有的研究基础上,对带暗牛腿的预应力装配式节点的力学性能系统开展了试验研究、有限元模拟和理论分析,完成的主要工作及得到的研究成果如下:(1)针对带暗牛腿的预应力装配式混凝土框架节点开展了拟静力荷载试验研究,系统分析了带暗牛腿的预应力装配式混凝土框架节点在低周往复荷载作用下的破坏形态、延性性能、耗能能力、残余变形、节点刚度、节点强度等。同时与整体现浇式混凝土框架节点的对比试验分析可知:带暗牛腿的预应力装配式混凝土框架节点具有等同于、甚至超越现浇整体式混凝土框架节点的强度及刚度的特点,同时带暗牛腿的预应力装配式混凝土框架节点可以在往复荷载作用下可产生较大的几何变形,且其具有良好的自复位能力,其破坏形态主要表现为暗牛腿位置处的混凝土斜压破坏。(2)运用ABAQUS软件对带暗牛腿的预应力装配式混凝土框架中节点建立了有限元模型。通过与试验结果的对比验证了有限元模型的正确性。借助带暗牛腿的预应力装配式混凝土框架中节点的有限元模型,研究了安装阻尼器的暗牛腿预应力装配式混凝土框架中节点的滞回耗能性能;针对采用CFRP加固暗牛腿的预应力装配式混凝土框架中节点的破坏形态开展了系列的有限元分析。分析结果表明:安装了阻尼器的预应力装配式混凝土框架中节点的耗能能力会大大提高;CFRP对节点的薄弱部位(暗牛腿)具有良好的加固效果。(3)结合带暗牛腿的预应力装配式混凝土框架节点的试验结果,对带暗牛腿的预应力装配式混凝土框架节点开展了理论模型研究。通过定义带暗牛腿的预应力装配式混凝土框架节点的相关极限状态,求得各极限状态下所对应的荷载和位移,进而求得其骨架曲线。同时根据推导得出的荷载位移方程,得到带暗牛腿的预应力装配式混凝土框架节点在受力过程中的刚度变化特点。更多还原

【Abstract】 Prefabricated building is one of the important construction methods that adapt to the development of the times.It has the advantages of short construction period,fast construction speed,low environmental pollution,and resource conservation.Incorporating prestressing technology into the design of prefabricated buildings can effectively solve the problem of node connection of prefabricated buildings,so as to greatly improve the safety performance of prefabricated buildings.Based on this,the research on the mechanical properties of prestressed assembled nodes has important practical engineering significance and broad application prospects.Since the research of prestressed prefabricated joints in China is still in its infancy,it lacks perfect design methods and standard systems.Based on the existing research,this paper carried out experimental research,finite element simulation and theoretical analysis on the mechanical performance system of prestressed assembled nodes with hidden corbels.The main work completed and the research results obtained are as follows:(1)A quasi-static load test study was carried out on the prestressed prefabricated concrete frame joints with hidden corbels,and the failure form of the prestressed prefabricated concrete frame joints with hidden corbels under low-cycle reciprocating load was systematically analyzed,Ductility,energy dissipation capacity,residual deformation,node stiffness,node strength,etc.At the same time,the comparison test analysis with the integral cast-in-place concrete frame joints shows that the prestressed assembled concrete frame joints with hidden corbels have the characteristics of equal to or even surpass the strength and rigidity of the cast-in-place integral concrete frame joints,the prestressed prefabricated concrete frame joints with hidden corbels can produce large geometric deformation under the action of reciprocating load,and it has good self-reset ability.Its failure form is mainly reflected by the concrete baroclinic failure at the location of the hidden corbel.(2)ABAQUS software is used to establish a finite element model of the nodes in the prestressed concrete frame with hidden corbels.The correctness of the finite element model is verified by comparison with the test results.With the help of the finite element model of the nodes in the prestressed concrete frame with hidden corbels,the hysteretic energy dissipation performance of the nodes in the prestressed concrete frame with dampers was studied;A series of finite element analyses were carried out on the failure forms of the nodes in the prestressed concrete frame.The analysis results show that the energy dissipation capacity of the nodes in the prestressed concrete frame with dampers will be greatly improved;CFRP has a good reinforcement effect on the weak parts(hidden corbels)of the nodes.(3)Combined with the test results of prestressed concrete frame joints with hidden corbels,a theoretical model study was carried out on the prestressed concrete frame joints with hidden corbels.By defining the relevant limit states of the prestressed concrete frame joints with hidden corbels,the corresponding load and displacement under each limit state are obtained,and then the skeleton curve is obtained.At the same time,according to the derived load-displacement equation,the stiffness variation characteristics of the prestressed concrete frame joints with hidden corbels during the loading process are obtained.更多还原