Study On Structure And Mechanical Performance Of Original Bamboo Beam Column Bayonet Joint

In the original bamboo building,the bearing capacity and stiffness of the beam-column connection node,as the key to the structure,directly affect the overall strength,durability and stability of the frame structure.With the gradual application of raw bamboo structure,local governments vigorously advocate green ecological architecture for the realization of urban ecological livability and rural industrial revitalization.A variety of bamboo lodges,villas,community pavilions,scenic spots,Dai new dwellings and other characteristics of the original bamboo structure of the broad construction of the use of demand for the original bamboo nodes of structural form and mechanical properties put forward higher requirements.Traditional raw bamboo nodes have problems such as insufficient bearing capacity,insufficient stiffness and poor durability in actual projects.The research on the force of new raw bamboo nodes is still not comprehensive,lack of corresponding specification,low construction efficiency and difficult to industrialize production;the calculation theory of raw bamboo structure is also not perfect,lack of construction guidance.Therefore,in order to meet the requirements of modern bamboo node assembly development ideas,this paper designs a node form that is easy to assemble,less harmful to raw bamboo material,low level of installation technology requirements,excellent mechanical properties and universal applicability.By using a combination of simulation,theory and experiment,the force performance of this kind of raw bamboo beam-column hug-joint node is studied,and the main research work and results are as follows.(1)Improvement and innovation of the traditional raw bamboo nodes.In this paper,three kinds of raw bamboo assembled nodes were designed by reviewing relevant domestic and foreign data,and ANSYS finite element trial calculations were conducted to provide data indicators for subsequent tests to determine the magnitude of loading devices and preloading forces.(2)Monotonic loading tests were carried out on three types of nodes with a total of nine specimens.The node damage morphology,moment-turn angle curve,load-displacement curve and moment-strain curve are mainly studied to obtain the stress characteristics,initial stiffness,stiffness,bearing capacity and stress variation of the raw bamboo and steel connectors for each type of nodes.The nodes were analyzed and verified for semi-rigidity to provide a physical model of stiffness for the finite element analysis of the raw bamboo frame structure later on.Comparison with existing raw bamboo nodes is made to comprehensively evaluate the optimization performance based on the mechanical properties of the nodes.(3)Low-period repeated loading tests were conducted on three types of nodes with a total of six specimens.The damage morphology,hysteresis curve,skeleton curve,stiffness degradation and energy dissipation capacity of the nodes were mainly studied.To investigate the influence of two factors,the form of construction and the original bamboo grade,on the seismic performance of the nodes.(4)Through the analysis of experimental data,the node form with the best mechanical properties was selected,and the single-tube bundle node was optimized into a double-tube bundle node to be applied to the actual project.Using finite element software to simplify the model,the nonlinear analysis under earthquake action is carried out to verify that the nodal connection stiffness of the bamboo structure can meet the normal use requirements of the original bamboo frame.The optimization of steel connectors,bamboo material preference and bond-slip phenomenon treatment methods are given in conjunction with the experimental phenomena,and prefabrication production and construction suggestions are given in terms of engineering applications for practical engineering reference.