传统木结构典型榫卯节点基于摩擦机理特性的低周反复加载试验研究

为研究榫卯节点接触面间的摩擦效应对榫卯节点减震耗能能力的影响，通过改变榫卯节点接触面间的摩擦系数，对3种古建筑中常用的透榫节点、燕尾榫、梁下有枋透榫节点模型进行低周反复荷载试验，并对基于摩擦特性的节点耗能能力的影响进行量化分析。研究结果表明：摩擦对3类节点的破坏形态、承载力及延性影响不大；透榫及梁下有枋透榫节点滞回曲线呈现出典型的反Z形，捏缩效应比较明显，且摩擦系数小的模型滞回环面积明显小于摩擦系数大的模型，燕尾榫节点滞回曲线较为饱满，未出现明显捏缩效应，摩擦系数改变对燕尾榫节点滞回环面积影响较小；摩擦对透榫及梁下有枋透榫节点初始刚度影响较大;透榫节点摩擦系数为0.38时的等效黏滞阻尼系数是摩擦系数为0.20时的2倍多，梁下有枋节点摩擦系数为0.38时的等效黏滞阻尼系数是摩擦系数为0.20时的1.4倍，摩擦对燕尾榫节点等效黏滞阻尼系数的影响主要体现在对节点耗能能力达到峰值的发挥速度上。

Low-cycle reversed loading tests study on typical mortise-tenon joints of traditional timber building based on friction mechanism

The friction effect between mortise-tenon joints interface of the timber structures has a significant effect on damping energy dissipation. In order to study the influence of friction coefficient on seismic performance of typical mortise-tenon joints, three typical joints with different friction coefficients were tested by low-cycle reversed loading, including two through tenons, two dovetail tenons and two fang under through tenons, and were analyzed by means of quantitative research method. The results indicate that the failure patterns，bearing capacity and ductility of the joints are not significantly influenced by the friction. The shapes of hysteretic loops of all joints except dovetail tenons are reverse Z shape and the pinching effect gets obvious. The area of hysteretic loops of model with friction coefficient of 0.2 is much smaller than that of the model with friction coefficient of 0.38. Hysteretic loops of the dovetail tenons are relatively full and the pinching effect is not obvious. The change of friction coefficient has smaller influence on area of hysteretic loops of the dovetail tenons. The influence of friction on the initial stiffness of through tenons and fang under through tenons is great. The equivalent viscous damping coefficient of through tenon joints model with friction coefficient of 0.38 is twice as big as that of the model with friction coefficient of 0.20. For fang under through tenons joints, the model with friction coefficient of 0.38 is 1.4 times as much as the model with friction coefficient of 020. The impact of the friction of the dovetail joint is mainly reflected by the speed to achieve the peak energy dissipation of the joints.