带空隙透榫节点弯矩-转角关系理论分析

摘要

为研究带空隙的典型不对称榫卯节点——透榫节点的弯矩-转角关系,构建了节点的埋置嵌压作用力学模型.通过建立平衡方程、物理方程及几何关系,推导了节点的弯矩-转角理论计算公式,并与试验结果进行了对比,分析表明:理论计算结果与试验结果吻合较好.进一步定量分析了空隙g以及摩擦因数μ对节点弯矩和初始转动刚度的影响,结果表明:随着空隙g的增大,透榫节点正反向初始转动刚度均逐渐减小,且与空隙g基本呈线性变化;正反向加载情况下,透榫节点弯矩和转动刚度均随摩擦因数的增大而逐渐增大,尤其在节点屈服后表现更加突出;节点间空隙是节点弯矩和转动刚度的主要影响因素,摩擦因数对节点弯矩和转动刚度的影响略小于空隙的影响.所得结果可为古建筑木结构的加固保护提供理论依据.%To analyze the moment-rotation relationship of the representative asymmetric mortise-tenon joint to through-tenon joint with gap,an embedment model of joint was constructed.The moment-rotation calculation formula of through-tenon joint was deduced by establishing the relationships of forces,materi-als and geometries.Existing tests approved that the theoretical calculation results agreed well with the test results.Furthermore,the effects of the gap g and the friction coefficientsμon bending moment and initial rotation stiffness of the joint were analyzed quantitatively,and the results showed that:the positive and negative initial rotation stiffness of the through-tenon joint decreased with the increasing gap g,and there is a linear change between them.The bending moment and rotational stiffness of the joint increased as the friction coefficient increased under the positive and negative loading,and they have a significant change,especially when the joint yields.Gap in joint is a main influence factor on the bending moment and rota-tional stiffness of the joint,and the influence of friction coefficient on the bending moment and rotational stiffness of the joint is slightly less than that of the gap.The study in this paper provides theoretical basis for the mechanics analysis of ancient timber framed buildings.