基于非线性摩擦接触的两种索撑节点数值模拟

Numerical simulation of two common cable-strut joints based on nonlinear friction contact

索撑节点是张弦结构中的重要部件,拉索的摩擦及节点水平夹角不但引起预应力的损失,而且和复杂受力等因素一起直接影响着节点的抗滑移性能,决定着结构整体可靠性。结合某80m张弦桁架工程,对两种常见的张弦结构索撑节点考虑非线性摩擦接触,利用ANSYS分析了摩擦系数与节点角度对预应力损失的影响,并在不同的螺栓预紧力作用下,分析节点的抗滑移性能,得到了螺栓预紧力与拉索摩擦应力及节点滑移距离的关系。分析结果表明:不同摩擦系数及预拉力作用下,两种节点的预应力损失率最大均不会超过3%;板式节点的最大摩擦应力比球式节点小45.4%,滑移距离比球式节点大50.8%,而摩擦力比球式节点大255%。

The cable-strut joints are the key components of the beam string structure.The friction of the cable and the angle of the joints will cause the pre-stress loss.Those factors and complex stress of the cable directly affect the anti-sliding performance of the joints,also determine the overall reliability of the structure.Based on an 80 m truss string project,the nonlinear friction contact was considered for two common cable-strut joints of beam string structure.The influence of friction coefficient and joint angle on pre-stress loss was analyzed by ANSYS.The anti-sliding performance of joints was analyzed under different bolt pretension,and the relationship between bolt pretension and cable friction stress and joint slip distance was obtained.The results show that under different friction coefficient and pretension,the maximum pre-stress loss ratio of the two joints would not exceed 3%.The maximum friction stress of plate joint was 45.4%less than spherical joint,however,the slip distance was 50.8%and the friction force was 255%larger than that of spherical joint.