有螺栓预紧力的T型连接初始刚度计算方法

Calculation method of initial stiffness of T-stubs involved bolt pretension

为深入了解螺栓预紧力对T型连接初始刚度的影响,基于连续梁模型对有预紧力时不考虑和考虑螺栓抗弯刚度的T型连接初始刚度计算方法进行了研究,给出了其初始刚度的计算公式.对影响T型连接初始刚度的翼缘厚度和螺栓位置进行了参数分析,得到不同参数对有预紧力T型连接初始刚度的影响规律.研究结果表明,随着螺栓轴线至翼缘边缘距离的增大和翼缘厚度的减小,螺栓抗弯刚度对连接初始刚度的影响逐渐增大.对于有螺栓预紧力的普通钢T型连接,考虑螺栓抗弯刚度时初始刚度的计算结果较不考虑时提高约6%;但对于有螺栓预紧力的高强钢T型连接,考虑螺栓抗弯刚度的计算结果较不考虑时提高约30%.因此,对于有螺栓预紧力的高强钢T型连接,计算其初始刚度时不可忽略螺栓的抗弯刚度.

To reveal more information on the influence of bolt pretension on the initial stiffness of T-stubs, theoretical researches based on the continuous beam model were presented on the calculation method of the initial stiffness of the T-stubs involved bolt pretention considering bending stiffness of bolts or not. A series of equations for predicting the initial stiffness of the T-stubs were derived. The parametric analysis was conducted on the flange thicknesses and locations of the bolts of the T-stubs. Their influences on the initial stiffness of the T-stubs were presented. The research results show that with the increase of the flange thicknesses and the decrease of the distance between the axis of the bolts and the edges of the flanges, the influence of the bending stiffness of the bolts on the initial stiffness of the T-stubs increases. For the mild steel T-stubs with bolt pretension, the calculated results of the initial stiffness considering the bending stiffness of the bolts are nearly 6% higher than those without considering the bending stiffness. But for the hollow structural sections (HSS) T-stubs with bolt pretension, the initial stiffness considering the bending stiffness of the bolts are higher by nearly 30% than those without considering the bending stiffness. Therefore, for the HSS T-stubs with bolt pretension, the bending stiffness of the bolts cannot be neglected when calculating the initial stiffness of the T-stubs.