| The ancient timber buildings embodies the wisdom left over from the Chinese ancestors for thousands of years.They have important scientific,cultural,and artistic features.Among them,an important feature of the ancient architectural wooden structure is that the structural framework pieces are connected with mortise-tenon.Mortise-tenon joint have advantages of high energy consumption and strong deformability.However,due to the material properties of wood itself,defects often lead to very serious damage,affecting the structural safety at a later stage.In order to preserve the valuable treasures left by our ancestors,the reinforcement and repair of wooden structures and knots has become an important issue that needs urgent solution.The main research work this paper accomplished is as follows:(1)A friction damper was designed and manufactured for the joints of wooden structures,and a pseudo-static test was performed on the unconsolidated one-way straight tenon joint and one-way straight tenon joint with friction dampers.Considering the influence of different friction coefficients and pre-tightening forces on the friction damper,the hysteresis curve,skeleton curve,stiffness degradation curve,and equivalent of the two-way reinforced joints with two friction dampers are compared.The viscous damping coefficient and other seismic indicators show that the friction damper performs well in improving the seismic performance of the joints,and it is helpful to improve the stiffness and energy dissipation performance of joints.(2)During the test,the variation of the axial force during the loading of the friction plate preloading bolt and the change of the mutual rotation angle between the friction plates with the loading displacement were measured.Based on the analysis of these data,combined with experimental phenomena,the main factors influencing the work of the friction damper are obtained,including the compression of the beam and column by the friction damper,the loss of thickness of the friction plate during loading,and the axial force of the pre-tightening bolt.Impact on friction dampers etc.(3)Based on the experimental research,the ABAQUS software was used to perform finite element simulation on the one-way straight joints with friction dampers,and the calculated results were compared with the experimental results,including hysteresis curves,skeleton curves,and stiffnesses.Degradation curve and energy dissipation performance.The stress distribution of nodes at different loading displacements was analyzed.The final results of the finite element simulation are basically consistent with the test results.(4)In the end,some problems existing in the one-way straight boring node with a friction damper are summarized,and future research directions are proposed. |
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