桥梁半平行钢丝索的非对称断丝损伤力学模型

Damage Model of Multilayered Semi parallel Wire Cables with Non symmetric Wire Breaks

摘要:

桥梁用半平行钢丝索由于外层钢丝的螺旋外形和特殊构造，不能直接应用基于平行钢丝假定的并联模型或钢绞线模型进行力学分析.基于Love曲杆理论，考虑非对称断丝引起的垂直于拉索轴向的侧向位移，以及钢丝间的接触力和摩擦力的影响，建立静力拉伸荷载下半平行钢丝索的非对称断丝力学模型，通过数值计算和参数分析，研究断丝后索体内钢丝拉力分布规律及其影响因素.结果表明，非对称断丝引起明显的钢丝拉力不均匀分布，钢丝间摩擦系数、断丝径向位置对钢丝拉力分布影响最大.

Abstract:

Strands model or parallel model based on the assumption of parallel wires is helpless to a mechanical analysis of semi parallel wire cable for its helical characteristics and complex structure. Based on the theory of Love’s curved bar, the mechanical model for multilayered semi parallel wire cables under static tensile loads with non symmetric wire breaks were derived with a consideration of the deflections perpendicular to the tendon axis in the direction of the break wire, and the inter wire contact and friction. Distributions of wires’ axial force and related influence parameters are discussed by numerical calculation and parameter analysis. A comparison with the parallel model shows that non symmetric wire break leads to the marked non uniform distribution of wire axial force, and the parameters that affect the most the distribution of wire axial force are the inter wire friction coefficient and radial position of the break wire.