A round hollow steel section (HSS) is generally used in a wind turbine tower column. Experimental studies on the cyclic flexural behavior of round HSS columns with large diameter-to-thickness (D/t) ratios are very limited. Three steel round HSS column specimens with a D/t ratio of 240 were planned for tests. The specimens, made from ASTM A36 steel, had a clear height of 4390 mm, diameter of 1440 mm and thickness of 6 mm. In addition, one specimen was wrapped with the Glass Fiber Reinforced Polymer (GFRP) material. Specimen 1 was tested under an increasingly monotonic loading, and Specimens 2 and 3 were tested under an increasingly cyclic loading. Specimens 1 and 2 exhibited inward local buckling at a drift angle of 0.0025 rad.; Specimen 3 with GFRP wrapping at the bottom end exhibited inward local buckling at a drift angle of 0.003 rad., slightly later than the timing when the local buckling occurred in Specimens 1 and 2. Test results indicated that the ductility of Specimen 1 under the monotonic loading is larger than that of Specimens 2 and 3 under the cyclic loading due to slower strength degradation. Specimen 2 has a ductility of 1.02–1.65 before the lateral load decreases more than 10%. The maximum flexural strength of the GFRP-wrapped column increases 6%–10% compared to that without GFRP wrapping. The AISC (2016) and EN1993-1-6 (2017) standards reasonably predict the flexural strength of specimens, but the ASME (2006) and ASCE (2011) standards underestimate the flexural strength by 18%–25%. Nonlinear time–history analyses were conducted on a 10-MW wind turbine tower to develop a cyclic displacement protocol for the tests.

圆形空心钢截面（HSS）通常用于风力涡轮机塔柱。对具有大直径与厚度 ( D/t ) 比的圆形 HSS 柱的循环弯曲行为的实验研究非常有限。三个带D/t 的钢圆 HSS 柱试样计划测试的比例为 240。试样由 ASTM A36 钢制成，净高为 4390 毫米，直径为 1440 毫米，厚度为 6 毫米。此外，一个样品用玻璃纤维增​​强聚合物 (GFRP) 材料包裹。试样 1 在越来越单调的载荷下进行测试，试样 2 和 3 在越来越多的循环载荷下进行测试。试样 1 和 2 在 0.0025 弧度的漂移角下表现出向内局部屈曲；试件 3 底端包覆 GFRP 出现向内局部屈曲，漂移角为 0.003 rad.，略晚于试件 1 和试件 2 发生局部屈曲的时间。测试结果表明，试件 1 在单调作用下的延展性由于强度衰减较慢，循环载荷下的载荷大于试样 2 和试样 3。试样 2 在横向载荷下降超过 10% 之前具有 1.02-1.65 的延展性。GFRP 包覆柱的最大抗弯强度比未包覆 GFRP 柱的最大抗弯强度提高了 6%~10%。AISC（2016）和EN1993-1-6（2017）标准合理预测了试件的抗弯强度，但ASME（2006）和ASCE（2011）标准对抗弯强度的估计低估了18%~25%。对 10 兆瓦风力涡轮机塔架进行非线性时程分析，以开发用于测试的循环位移协议。但 ASME (2006) 和 ASCE (2011) 标准将抗弯强度低估了 18%–25%。对 10 兆瓦风力涡轮机塔架进行非线性时程分析，以开发用于测试的循环位移协议。但 ASME (2006) 和 ASCE (2011) 标准将抗弯强度低估了 18%–25%。对 10 兆瓦风力涡轮机塔架进行非线性时程分析，以开发用于测试的循环位移协议。