螺栓被连接件刚度理论的计算方法

为了更准确地计算螺栓被连接件的刚度,引入了假设垂直螺栓轴线的受压层在径向位置压应力的4次关系式,推导了被连接件刚度的计算公式.结合有限元分析及插值计算方法,获得了不同材料、不同尺寸所对应被连接件的刚度,反算出了相应的半顶角,进而拟合出了半顶角的解析式.同时,采用I-Scan压力测量系统测得了被连接件结合面的压力分布数据,得到了实际的半顶角.实验结果表明,半顶角解析解的误差小于2°,与有限元分析结果相比,被连接件刚度的计算误差小于6％,因此所推公式可准确地计算被连接件的刚度.

Theoretical Analysis for Bolted Member Stiffness

In order to accurately compute the axial stiffness of bolted members,the compressive stress of each compressive section perpendicular to the bolt axis is assumed as a quartic equation of the radial size.Following this assumption,new formulas for member stiffness are derived.Finite element analysis and its interpolation algorithms are conducted to calculate the stiffness of members with different materials and geometrical sizes.The obtained member stiffness is used to inversely calculate the corresponding semi-apex angle.Moreover,the real semi-apex angle is obtained from the contact pressure data of the member interface which is measured with the I-Scan system.The experimental results show good coincidence with the analytical semi-apex angles,and the corresponding error is within 2°.On the basis of the above derived formulas for the semi-apex angle and the member stiffness,the axial stiffness is calculated for bolted members with different materials and geometrical sizes.Compared with the finite element analysis,the errors of obtained member stiffness get less than 6%,so the member stiffness can be accurately calculated with the proposed method.