FE Analyses Of Dovetail Joint And Shizigutou Mortise-tenon's Seismic Performance

This paper researches on the seismic performance of wood construction,and carries on the theoretical analysis from building materials selection,structure features and structural measures,etc.Numerical simulation experiment is carried out by making use of the finite element analysis software ABAQUS to establish three dovetail mortise nodes column frame model and two head hoop tenon column frame model.And it gives the contrast analysis of the influence of gaps between the mortise and tenon joint on seismic performance of buildings specific work and the analysis results are as follows:1.It simply introduces the research background of ancient Chinese architecture,summarizes the development of Chinese ancient architecture and the main characteristics of each stage.Also it shows the research status both at home and abroad and research significance of this paper.2.It outlines the features of wood structure from two aspects of the structure and material,and analyses the advantage of wood as a construction material and the main mechanical properties of wood.It gives brief analysis of the wood structure building layout,big roof structure and column frame bearing the structure characteristics.The article introduces the structural characteristics and seismic mechanism of timber,mortise tenon joint nodes,and column feet flat pendulum.3.In view of the proposed numerical simulation test,it makes static analysis of dovetail joint and cross shizigutou mortise-tenon as test object.And we can have a preliminary understanding of the mechanical characteristics of two kinds of nodes.It introduced the “Caixiezhi” and the “Doukouzhi” which are both ancient common modulus system.Also it determined the size and weight load of test model.4.According to “Yingzaofashi”,it established dovetail mortise nodes column framemodel.And it set different type of nodes gap for two models.So it formed a seamless,end-gap and three sides gap(which is with round seam)dovetail mortise nodes column frame model control group.Two shizigutou mortise-tenon column frame models are set up and one of them is set with gap to form seamless and tenon joint hoop head with node column frame model control group.It respectively made simulation experiment of five models in three levels under the action of counterweight.After sorting test data,it got the hysteresis curves,skeleton curves,rigidity degradation curve and failure form of the model.(1)By the hysteresis curve: the hysteresis curve of dovetail node models and shizigutou mortise-tenon models all have “pinch shrinkage ” phenomenon,and with the increase of the upper weight load,“pinch shrinkage” phenomenon is more and more obvious.Overall,the hysteresis curve's plumpness of models with mortise and tenon joint group is poorer than seamless models.For dovetail mortise nodes,end gap model of hysteresis curve and seamless model hysteresis curve shape is not significantly different,but it has low horizontal stiffness.It can be thought that seismic energy dissipation of side seam to dovetail node is weakened slightly.It shows that mortise tenon joint gap weakens the hysteresis energy dissipation capacity of mortise tenon joint node.(2)By the skeleton curve and stiffness degradation curve: Under the influence of the same vertical load,the stiffness of seamless mortise and tenon joint nodes column frame model are larger than the gap model's.At the same time,the stiffness of dovetail joint model with side seam is greater than the dovetail model with circumferential seam.For the same model,the greater the vertical load of balancing,the greater the horizontal stiffness.Each model has obvious stiffness degradation phenomenon,and under different vertical weight load,each model's stiffness degradation results tend to be the same.Comparing the seamless model,gap model's stiffness degradation rate is greater.All of these show mortise and tenon joint gap have weaken the stiffness of mortise and tenon joint nodes.(3)According to the hysteresis curve and skeleton curve,the following models are made out: four parameters restoring force model of dovetail column frame model with side seam and seamless,three parameters restoring force model of dovetail column frame model with round seam,double broken line model with the seamless shizigutou mortise-tenon column frame,and three line mechanics model of shizigutou mortise-tenon frame model.(4)It gives the brief analysis of the dovetail node destruction form and the characteristics of tenon pull out.The failure pattern for shizigutou mortise-tenon node is the bottom of the mouth of the bending damage.(5)It is thought that dovetail joint has better friction and deformation capacity.In the ancient buildings,setting dovetail joint is beneficial to structural seismic.shizigutou mortise-tenon has greater lateral stiffness,which can improve the overall stability of the structure.