In engineering structures, steel strands can be subjected to dynamic loads associated with earthquakes, vehicle impacts, explosions and other special circumstances occurring in addition to static loads and resulting in higher strain rates. Therefore, it is of great significance to study the mechanical performance of steel strands subjected to dynamic loads at high strain rates. In this study, first an electrohydraulic high-speed impact test system, an electrohydraulic servo shear-stress test system, and a universal testing machine were used to conduct the dynamic tensile tests on single-wire, single-bundle, and four-bundle steel strands at ten different strain rates (2.73 × 10⁻³–10.714 s⁻¹), and the influences of the strain rate and strand diameter on the mechanical behavior of steel strands were analyzed based on the experimental data. At the same time, the wire breakage, failure modes, and fracture forms were analyzed, and the Ramberg-Osgood and Johnson-Cook constitutive models were revised to obtain a constitutive relationship which, along with the related material parameters, better describes the stress–strain behavior of the tensile steel strands subjected to dynamic tensile loads. The results show that the steel strands are clearly sensitive to strain rate, which is higher in quasi-static states and at low strain rates. At higher strain rates, the sensitivity to strain rate decreases, and the sensitivity of yield strength is higher than the ultimate strength. The strand diameter has certain influence on the steel strands performance. The ultimate strains of the single-wire and four-bundle steel strands are all smaller than that of the single-bundle steel strands. Twisting of the single-bundle steel strands weakened the wires and resulted in premature wire breakage. The failure modes of steel strands subjected to different tensile strain rates shifted from ductile to brittle. The failure modes were mainly of three types, namely, necking-milling, splitting-milling, and splitting. The Ramberg-Osgood and the Johnson-Cook constitutive models with the Cowper-Symonds strain rate parameter correction can more accurately reflect the variation in the strain hardening characteristics of steel strands with strain rate.

在工程结构中，钢绞线除了承受静态载荷外，还可能承受与地震，车辆撞击，爆炸和其他特殊情况相关的动态载荷，从而导致较高的应变率。因此，研究高应变率动态载荷下钢绞线的力学性能具有重要意义。在这项研究中，首先使用了电动液压高速冲击试验系统，电动液压伺服剪切应力试验系统和通用试验机对单线，单束和四束钢进行了动态拉伸试验。股以十种不同的应变速率（2.73×10 ^-3 –10.714 s ^-1），并根据实验数据分析了应变速率和线束直径对钢绞线力学性能的影响。同时，分析了断线，破坏模式和断裂形式，并对Ramberg-Osgood和Johnson-Cook本构模型进行了修改，以获得本构关系，并与相关的材料参数一起更好地描述了应力–承受动态拉伸载荷的拉伸钢绞线的应变特性。结果表明，钢绞线对应变率明显敏感，在准静态和较低应变率下应变率较高。在较高的应变速率下，对应变速率的敏感性降低，并且屈服强度的敏感性高于极限强度。钢绞线直径对钢绞线性能有一定影响。单线和四束钢绞线的极限应变均小于单束钢绞线的极限应变。单束钢绞线的扭曲会弱化钢丝，并导致钢丝过早断裂。承受不同拉伸应变率的钢绞线的破坏模式从韧性转变为脆性。失效模式主要有颈缩铣削，劈裂铣削和劈裂三种类型。带有Cowper-Symonds应变速率参数校正的Ramberg-Osgood和Johnson-Cook本构模型可以更准确地反映钢绞线的应变硬化特性随应变速率的变化。单线和四束钢绞线的极限应变均小于单束钢绞线的极限应变。单束钢绞线的扭曲会弱化钢丝，并导致钢丝过早断裂。承受不同拉伸应变率的钢绞线的破坏模式从韧性转变为脆性。失效模式主要有颈缩铣削，劈裂铣削和劈裂三种类型。带有Cowper-Symonds应变速率参数校正的Ramberg-Osgood和Johnson-Cook本构模型可以更准确地反映钢绞线的应变硬化特性随应变速率的变化。单线和四束钢绞线的极限应变均小于单束钢绞线的极限应变。单束钢绞线的扭曲会弱化钢丝，并导致钢丝过早断裂。承受不同拉伸应变率的钢绞线的破坏模式从韧性转变为脆性。失效模式主要有颈缩铣削，劈裂铣削和劈裂三种类型。带有Cowper-Symonds应变速率参数校正的Ramberg-Osgood和Johnson-Cook本构模型可以更准确地反映钢绞线的应变硬化特性随应变速率的变化。承受不同拉伸应变率的钢绞线的破坏模式从韧性转变为脆性。失效模式主要有颈缩铣削，劈裂铣削和劈裂三种类型。带有Cowper-Symonds应变速率参数校正的Ramberg-Osgood和Johnson-Cook本构模型可以更准确地反映钢绞线的应变硬化特性随应变速率的变化。承受不同拉伸应变率的钢绞线的破坏模式从韧性转变为脆性。失效模式主要有颈缩铣削，劈裂铣削和劈裂三种类型。带有Cowper-Symonds应变速率参数校正的Ramberg-Osgood和Johnson-Cook本构模型可以更准确地反映钢绞线的应变硬化特性随应变速率的变化。