Abstract: In order to explore the influence rule of laying types on the service performance of the multi-layer structure wire rope strands, the mechanical properties of the cross-twisted and co-direction twisted multi-layer structure wire rope strands were comparatively analyzed. Firstly, the parametric equations of the cross-twisted and co-direction twisted multi-layer structure wire rope strands were derived, and the geometric models of the two kinds of strands were established. Furtherly, with the consideration of the factors such as the laying types, the elasto-plasticity of the steel wires and the interwire frictional contact, the overall and local performances of the strands subjected to an axial tension were compared and analyzed through finite element simulation. The results show that the axial force and von Mises stress of the cross-twisted and co-direction twisted strands subjected to the same axial tensile strain are close to each other, and both of them have the nonlinear behavior. The plastic deformation of the cross-twisted strand is larger than that of the co-direction twisted strand. The stress distribution of the two is generally uniform. The stress of the cross-twisted strand is concentrated on the contact part between the inner helical layer and outer helical layer, while that of the co-direction twisted strand is concentrated between the core layer and inner helical layer. Compared with the co-direction twisted strand, the cross-twisted strand has a better anti-rotation property and less stress concentration.

Key words: bridge engineering; multi-layer structure wire rope strand; laying type; performance comparison; finite element simulation; elasto-plasticity

摘要： 为探索桥梁中多层结构钢丝绳股服役特性受捻制方式的影响规律，对交互捻多层结构钢丝绳股和同向捻多层结构钢丝绳股进行了力学性能对比研究。为此，首先推导了交互捻和同向捻多层结构钢丝绳股的参数方程，并建立了两类绳股的几何模型；进而考虑捻制方式、钢丝弹塑性、丝间摩擦接触等因素，对两类绳股进行轴向拉伸有限元仿真，对比分析了二者整体性能以及局部性能。结果表明：相同轴向拉伸应变下，交互捻和同向捻绳股具有相近的轴向力和von Mises应力，且二者均表现为整体非线性行为；交互捻绳股塑性变形比同向捻绳股更大；二者应力分布总体均匀，交互捻绳股应力集中在内层侧丝与外层侧丝接触部位，而同向捻绳股应力集中在芯丝与内层侧丝接触部位，前者较后者具有更好的抗旋转性能，且产生较小的应力集中。

关键词: 桥梁工程；多层结构钢丝绳股；捻制类型；性能对比；有限元仿真；弹塑性