透榫节点的受弯性能

Flexural behavior of penetrated mortise-tenon joints

对透榫节点进行单调加载试验,获得其弯矩-转角关系曲线以及破坏形态,并运用有限元软件ABAQUS对榫头的变形状态和应力分布进行数值模拟.结合试验研究和数值模拟,建立了节点弯矩-转角关系的简化力学模型.研究结果表明:透榫节点正、反向加载时的破坏形态分别为榫头变截面处顺纹撕裂破坏和榫头下侧的受弯破坏;节点正向加载时的受弯承载力和极限转角小于反向加载时的受弯承载力和极限转角;节点的抵抗力矩主要由小出部位与卯口之间的相互作用来提供;榫头上侧缝隙对节点的初始滑移段影响显著;节点正、反向加载时的弯矩-转角关系均可简化为三折线模型.

The moment-rotation curves and the failure modes of penetrated mortise-tenon joints were obtained by monotonic loading experiments. The deformation states and the stress distributions of tenons were simulated by the finite element software ABAQUS. The simplified mechanics models of the moment-rotation relationships were built by combining experiments and numerical simulation.The research results showthat the failure modes of penetrated mortise-tenon joints under the positive and negative loading are tearing damage along the grain in the variable cross section and bending damage under the tenon,respectively. The flexural capacity and the extreme rotation under the positive loading are smaller than those under the negative loading. The resisting moment is mainly provided by the interface action between the penetrated part with the small section and the mortise. The top gaps on the tenons have a decisive effect on the initial slipping segment of the joints. The moment-rotation relationships under the positive and negative loading can be simplified as a trilinear model.