酒杯型输电塔损伤定位的识别方法

针对酒杯型大跨越输电塔结构在塔头节段具有刚度突变的特性,建立了基于模态双指标的损伤定位方法。通过对现有模态指标的对比,提出首先采用振型差指标判断酒杯型输电塔刚度突变处是否损伤,再利用模态柔度改变率指标定位输电塔其他节段的损伤,以克服单一模态指标易误报警的缺陷。分析了模态识别误差、不完备测点和环境因素对模态双指标方法的影响。采用实塔数值模拟分析的结果表明,该方法能根据环境激励较为准确地识别损伤发生的部位,测试误差、环境等因素对其损伤定位功能的影响较小,为该类塔架结构长期在线健康监测提供了损伤识别的方法支撑。

Detecting Damage Location of Cup-Towers

To identify the damage location of the cup-tower with abrupt change in stiffness along height direction,a method based on dual-indicator of modal is proposed.Vibration Mode Difference Index is used to identify the damage in the stiffness changing point of the cup-tower firstly,then the Modal Flexibility Index is used to detect other sections damage,so the false alarm is avoided.The influence of three factors,including environment,modal identification errors and incomplete measurement points,to the dual-indicator method are discussed.The numerical simulation calculations show that the method can identify the damage location effectively,and the three factors have little effect on damage localization.