中文摘要：

基于Love曲杆理论建立钢丝静力拉伸模型,由外荷载作用下单根钢丝平衡方程推导出钢丝轴力、弯矩、扭矩计算公式以及钢绞线截面弹性模量、抗弯刚度计算公式.利用Fortran编写程序,考察轴力变化时,钢丝螺旋角及钢绞线弹性模量、抗弯刚度等截面特性的变化规律.进一步研究了钢绞线弹性模量变化对结构受力性能影响及抗弯刚度变化对基频法计算拉索内力的影响.结果表明：随着钢绞线总轴力增加,钢丝螺旋角逐渐减小,钢绞线弹性模量和抗弯刚度逐渐增加;在外层钢丝螺旋角为0°即外层钢丝被拉直后,钢丝螺旋角和钢绞线弹性模量均不再变化;随着钢绞线总轴力进一步增加,钢丝半径和钢绞线抗弯刚度由于泊松效应影响略有减小.

英文摘要：

The static tension model of steel strand was established in this article based on the theory of Love′s curved bar theory .The expression of the axial force ,torque and bending moment can be ob-tained under the external load through the equilibrium equation of the helical wire .Besides ,the elastic modulus and the bending stiffness of the helical wire can be derived based on the static model .The re-lations of helical angle ,the elastic modulus and the bending stiffness with the external forces were ex-pressed by using Fortran language .Finally ,the influence of the elastic modulus of the steel strand on the performance of the structure and the influence of the bending stiffness of the steel strand deter-mined by the fundamental frequency were studied .The results indicate that the elastic modulus and bending stiffness increase with the increment of the axial force of steel strand ,while the helical angle decreases .The helical angle and elastic modulus remain constant when the helical angle becomes 0° . The radius of the steel wire and the bending stiffness of the steel strand decrease slightly due to the in-fluence of the Poisson effect when the axial force increases .