Research On Mechanical Properties Of The Tenon Of Ancient Huizhou Buildings After Repair And Reinforcement

With wooden structure as the main structural form,Huizhou ancient architecture is the carrier of Huizhou memory and has unique historical and cultural value.The old wooden frame will be damaged to varying degrees and needs to be repaired and strengthened.In recent years,many scholars have studied the mechanical mechanism of tenon joints in wood structures,and have achieved a lot of results,however there are few researches on the mechanical properties of joints after repair and reinforcement.This paper takes the double-span timber frame as the research object,conducts vertical static loading test and numerical simulation,and studies the mechanical properties of the double-span timber frame after tenon repair and reinforcement.The influence of different materials,different reinforcement methods and tenon placement methods on the mechanical properties of tenon-mortise joints is analyzed to find a scientific and reasonable reinforcement method.The main research contents and results are as follows:（1）Taking Dunmutang,Xucun,Shexian County as the prototype,a 1:2.72 scale test was carried out,and the mechanical characteristic parameters of the tenon joints were measured by the static test.The F-με,F-θ curves,load-displacement curves,pull tenoncorner curves and joint area deformations of side-column and central-column joints are analyzed.The semi-rigid characteristics of tenon-mortise joints are summarized.（2）The non-destructive pineapple lattice double-span timber frame was damaged due to the tensile failure at the bottom of the beam,and the failure load reached 310 KN.While the non-destructive Chinese fir double-span timber frame was damaged due to the buckling instability,and the failure load was only 70 KN.And the increase of tenon F-με curve,F-θcurve,load-displacement curve and extraction-angle curve is greater than that of nondestructive pineapple lattice.On the whole,the mechanical performance of the pineapple lattice material is better than that of the fir material.The placement method of the tenon has a great influence on the mechanical performance of the joint,and the F-θ curve of the edge-column tenon-mortise joint presents three stages,namely the slip stage,the elastic stage and the strengthening stage.However,the increase of the F-θ curve of the tenonmortise joint of the central column is larger than that of the tenon-mortise joint of the side column,which has no obvious elastic stage,showing the characteristics of "smoothing first" and "rising later".Under the same working conditions,the rotation angle,displacement and tenon extraction values of the tenon placed at the lower end are smaller than those of the tenon placed at the upper end.Sparrow under the tenon placed at the upper end is also more likely to generate eccentric force,so the way of placing the tenon end down is better than placing the tenon end above.（3）Two kinds of reinforcement schemes,local replacement and overall replacement of tenon,were studied by static load test,and the rationality of the tenon reinforcement method of wood frame after reinforcement was analyzed.The results show that compared with the non-destructive double-span timber frame nodes,the F-θ curve,load-displacement curve,and tenon-extraction curve of the locally replaced reinforcement node are not very different,which proves that the reinforcement scheme is reasonable.However,the failure load of the overall replacement reinforcement joint is relatively small,and the deformation of the reinforcement is too large,resulting in instability and failure.Under the same load,compared with the non-destructive double-span timber frame joints,the difference of the rotation angle reaches 0.09 rad,and the increase value reaches 50%.The maximum vertical displacement difference of the tenon is 4.78 mm,and the increase value reaches 50%.The results show that the overall replacement reinforcement scheme is less effective and lacks security,and the reason for the inconsistency with the actual project is that the overall replacement position and size are unreasonable,which should be verified by later research.（4）Numerical analysis is carried out on the double-span timber frame with nondestructive joints and replacement reinforcement joints,which verifies the accuracy of the test results and the reliability of the repair and reinforcement method,and provides a certain reference for future research on tenon repair and reinforcement.Figure [100] table [18] reference [63]...