A wind-tunnel study has been conducted to evaluate changes in the aerodynamic behaviour of stay cables of a bridge due to ice accretion from freezing rain and, due to different cable surface geometries. Numerical simulations were performed to predict the three-dimensional ice shapes resulting from freezing rain for a variation of environmental conditions: wind speed, wind direction, air temperature, velocity of precipitation and duration of precipitation. Stay-cable models were fabricated using laser selective sintering for three different surface geometries (double helical fillet, concentric rings, and double helical strakes) with ice formed under the same environmental conditions. Additional models with the helical fillet geometry were fabricated to evaluate the effect of the air temperature at which ice was formed, the effect of wind direction during the precipitation event and the effect of the duration of the precipitation. The aerodynamic drag and lift forces acting on the models were measured for different wind speeds and cable-wind angles. The overall study evaluated the mean aerodynamic force coefficients of ten models in smooth flow, and two of the models were also tested in turbulent flow. The critical Reynolds number regime for the models of stay cable with ice accretion shapes occurred at a lower Reynolds number (below 100,000) than for the un-iced cables and the drag coefficient was less sensitive to increases in Reynolds numbers than the equivalent un-iced cables. These effects were attributed to the combined role of the ice-shape in determining the separation point combined with the higher surface roughness of the ice. An important observation was that for the three surface geometries and the range of test conditions that were considered, the maximum drag coefficients for ice-accreted models ranged from approximately 1.1 to 1.3, and were up to 50% greater than those observed without ice. The model with helical strakes and ice accretion exhibited the highest drag coefficient and exhibited more variation in lift coefficient with changes in Reynolds number than the other two cable surface geometries. The aerodynamic forces of an ice-accreted model followed similar trends in smooth and turbulent flow, but the drag coefficients were greater in turbulent flow. The presence and shape of the ice appeared to have a more dominant effect on the separation behaviour of the models than the presence of turbulence (for an ice-accreted model). The aerodynamic coefficients did not change greatly between the cases where ice was accreted at $-0.5°\mathrm{C}$ and $-1.5°\mathrm{C}$ due to the similar ice shape and thickness near the separation locations. The ice shape formed at $-5°\mathrm{C}$ was thicker but more localized and resulted in drag and lift coefficients that had greater variation with changes in the cable-wind plane. The effect of ice duration from 10 h to 20 h resulted in a increased variation in mean lift coefficient behaviour due to the asymmetric shape that resulted from the ice accretion parameters.

已经进行了风洞研究，以评估由于冻雨积冰和不同的拉索表面几何形状引起的桥梁斜拉索空气动力学行为的变化。进行数值模拟以预测由于风速、风向、气温、降水速度和降水持续时间等环境条件变化而导致冻雨产生的三维冰形状。斜拉索模型是使用激光选择性烧结制造的，用于三种不同的表面几何形状（双螺旋圆角、同心环和双螺旋条纹），并在相同的环境条件下形成冰。制造了具有螺旋圆角几何形状的其他模型，以评估形成冰时的气温的影响，降水事件中风向的影响和降水持续时间的影响。针对不同的风速和电缆-风角，测量了作用在模型上的气动阻力和升力。整体研究评估了十个模型在平滑流中的平均气动力系数，其中两个模型也在湍流中进行了测试。具有积冰形状的斜拉索模型的临界雷诺数制度发生在比未结冰索更低的雷诺数（低于 100,000）时，阻力系数对雷诺数增加的敏感性低于等效的未结冰索电缆。这些影响归因于冰形状在确定分离点方面的综合作用以及冰的较高表面粗糙度。一个重要的观察结果是，对于所考虑的三种表面几何形状和测试条件范围，积冰模型的最大阻力系数范围从大约 1.1 到 1.3，并且比没有冰时观察到的模型大 50%。与其他两种缆索表面几何形状相比，具有螺旋纹和积冰的模型表现出最高的阻力系数，并且随着雷诺数的变化，升力系数的变化更大。积冰模型的空气动力在平滑和湍流中遵循相似的趋势，但在湍流中阻力系数更大。与湍流的存在（对于积冰模型）相比，冰的存在和形状似乎对模型的分离行为具有更大的影响。$-0.5°\mathrm{C}$ 和 $-1.5°\mathrm{C}$由于分离位置附近的冰形状和厚度相似。冰的形状形成于$-5°\mathrm{C}$更厚但更局部化，导致阻力和升力系数随着索风平面的变化而变化更大。由于积冰参数导致的不对称形状，冰持续时间从 10 小时到 20 小时的影响导致平均升力系数行为的变化增加。