古建筑木结构燕尾榫节点弯矩-转角关系理论分析

基于燕尾榫节点受力机理的分析,对燕尾榫节点的转动弯矩进行了理论分析,推导了燕尾榫节点弯矩-转角理论计算公式,并与试验结果进行了对比分析,理论分析结果与试验结果吻合较好;在计算公式的基础上,对燕尾榫节点转动弯矩的影响参数进行了分析,结果表明：在一定范围内,随着摩擦系数的增大,燕尾榫节点的转动弯矩和初始转动刚度也逐渐增大;当摩擦系数超过0.5时,节点的初始转动刚度增加幅度逐渐减小;榫头长度和榫头的“收乍”角度的增大均能够提高燕尾榫节点的转动弯矩以及初始转动刚度;榫头高度的增大能够一定程度地提高燕尾榫节点的转动弯矩,但对节点的初始转动刚度影响不大。所得结果可为古建筑木结构的受力分析提供依据。

THEORETICAL ANALYSIS ON MOMENT-ROTATION RELATIONSHIP OF DOVETAIL JOINTS FOR CHINESE ANCIENT TIMBER STRUCTURE BUILDINGS

Based on the analysis on the force mechanism of dovetail joints, their rotational moment was analyzed and a moment-rotation calculation formula was deduced. The existed test approved that the formula is accurate and the calculated result agrees well with the test result. According to the moment-rotation calculation formula, the factors affecting the rotational stiffness of dovetail joints were analyzed. The results show that: the rotational moment and initial rotational stiffness are increased as the increase of friction coefficients; the increase amplitude of initial rotational stiffness is reduced when the friction coefficient is more than 0.5; the rotational moment and initial rotational stiffness are improved with the increase of the length and angle of a tenon; the rofational moment is improved with the increase of the height of a tenon, but the initial rotational stiffness very little. The conclusions could provide a theoretical basis for the mechanics analysis of ancient timber structure buildings.