This article aims to investigate the contact characteristics of mortise and tenon (M&T) joints in the traditional timber structures. In particular, the normal embedded compressive contact between contact surfaces of M&T joint was investigated. Based on basic contact theory and contact characteristics between mortise and tenon, a normal elasto-plastic contact model, which can reflect the real normal contact behavior of M&T joints in traditional wooden structures, was proposed. Coulomb friction contact was utilized to describe the tangential slipping characteristics of the contact surfaces. Micro-morphology scanning tests of wood samples with different roughness were carried out to determine the parameters involved in the normal contact model. The normal contact model subroutine of M&T joint was compiled by FORTRAN language, implemented into ABAQUS through user-defined interface (UINTER). Then the proposed model was verified by shear tests of wood contact surfaces considering different normal pressures. Finally, a finite element model (FEM) of straight tenon joint subjected to cyclic reversed loading, based on the proposed normal elasto-plastic contact model, was developed, and a FEM considering normal “hard contact” between the contact surfaces, was also performed. The simulation results were validated by the experimental results. Results showed that the user-defined normal elasto-plastic contact FEM was more in line with the actual force state and mechanical behavior of M&T joints, which can more accurately predict the failure modes and simulate the hysteretic behavior of M&T joints, compared to the FEM considering normal “hard contact” of the contact surfaces.

中文翻译：

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榫and榫法向接触性能：理论分析与数值模拟

本文旨在研究榫眼和榫（M＆T）节点在传统木结构中的接触特性。特别地，研究了M＆T接头接触面之间的正常嵌入压缩接触。基于基本的接触理论和榫眼与榫contact的接触特性，提出了一种能反映传统木结构中M＆T接头真实的正常接触行为的普通弹塑性接触模型。库仑摩擦接触用于描述接触表面的切向滑动特性。对具有不同粗糙度的木材样品进行了微观形态扫描测试，以确定正常接触模型中涉及的参数。M＆T关节的普通接触模型子程序是用FORTRAN语言编写的，通过用户定义的接口（UINTER）实现到ABAQUS中。然后通过考虑不同法向压力的木材接触表面的剪切试验验证了所提出的模型。最后，基于提出的普通弹塑性接触模型，开发了承受反复反向载荷的直榫连接的有限元模型（FEM），并且还考虑了接触面之间的正常“硬接触”，进行了有限元分析。 。实验结果验证了仿真结果。结果表明，用户定义的普通弹塑性接触有限元法更符合M＆T接头的实际受力状态和力学行为，从而可以更准确地预测M＆T接头的失效模式并模拟滞后行为，