古建筑木结构透榫节点力学模型研究

为研究古建筑木结构透榫节点的M-θ力学模型，在分析透榫节点构造特征与受力机理的基础上，建立其数值模型，用透榫节点的试验数据验证了该数值模型的正确性，并分析了节点缝隙、木材横纹弹性模量和大榫头长度对透榫节点受弯承载力的影响。根据受力分析结果，建立以弹性点、屈服点与极限点为特征点的三折线多参数M-θ力学模型，其结果与多数的试验结果基本吻合，并将该力学模型应用于木构架的受力分析。研究结果表明：透榫节点的滞回耗能能力强，节点的变形主要集中在榫头处。当榫头与卯口之间的缝隙增大时，节点的受弯承载力降低。随木材横纹弹性模量的提高和大榫头长度的增加，节点的受弯承载力有一定提高。文章建立的M-θ力学模型能较好反映透榫节点的受力过程，适用于木构架的受力分析，其荷载 位移骨架曲线与试验结果基本吻合。研究成果可为古建筑木结构的维修与保护提供参考。

Study on mechanical model of through-tenon joints in ancient timber structures

To study the M-θ mechanical model of through-tenon joints in ancient timber structures，a numerical model is established based on the analysis results of structural characteristics and mechanical mechanism of through-tenon joints. The numerical model is verified with the experimental data of through-tenon joints. The influences of joint gap，transverse elastic modulus of timber，and length of the large tenon on the bending capacity of the joint are analyzed. Based on the results of stress analysis，a three-fold multi-parameter M-θ mechanical model is proposed，with elastic point，yield point，and ultimate point as characteristic points. The mechanical model can be verified with the test results and applied to the stress analysis of timber frames. Results show that the through-tenon joints have good energy dissipation capacity and the joint deformation mainly occurs at the tenon. The bending capacity of the joint decreases with the gap between tenon and mortise. Increasing transverse elastic modulus of timber and large tenon length can improve the bending capacity of the joint to a certain extent. The M-θ mechanical model can well reflect the mechanical properties of through-tenon joints. Application of the mechanical model to a previous timber frame test indicates that a good match between the model and experimental results. This research can provide good reference for the maintenance and protection of ancient timber structures.