基于应变统计矩的三管塔损伤识别方法研究

Damage identification method of three-tube tower based on strain statistical moments

为了预防通信铁塔结构安全事故的发生,并及时预警可能出现的损害,进行通信铁塔结构安全监测工作至关重要。以应变统计矩改变率作为损伤指标,针对三管塔结构进行损伤识别。通过理论推导建立了多自由度结构体系应变响应统计矩与结构刚度之间的关系,并提出应变四阶统计矩改变率损伤指标。通过建立应变四阶统计矩与应变能量密度之间的关系,依据最大应变能量密度原理,优化传感器布设,再通过设置不同信噪比,在风速风向改变的条件下,基于数值模型验证方法的有效性,并与其他损伤识别方法进行识别效果研究对比。同时,结合现场三管塔的实测应变数据进行分析。结果表明:该方法可优化传感器布设,能够降低成本并提高监测效率,可在20 dB环境噪音下识别三管塔损伤局部区域范围。

In order to prevent the occurrence of communication tower structural safety accidents and warn the possible damages in time,it is of vital significance to carry out the communication tower structural safety monitoring work.In this paper,a damage identification method for the three-tube tower structure was proposed by taking the changing rate of the statistical moment of strain as the damage index.The relationship between the strain response statistical moments and structural stiffness of multi-degree-of-freedom structural system was theoretically deduced,and the damage index of strain fourth-order statistical moment changing rate was proposed.By establishing the relationship between the fourth-order statistical moments of strain and the strain energy density,the sensor deployment was optimized based on the principle of maximum strain energy density.By setting different signal-to-noise ratios,the effectiveness of the method was verified based on numerical modeling under the condition of varied wind speed and direction,and the identification effect was compared with other damage identification methods.At the same time,it was analyzed in combination with the measured strain data of the three-tube towers on site.The results show that the method can optimize the sensor deployment,reduce the cost and improve the monitoring efficiency,and identify the damage of the three-tube tower in the local area range with 20 dB ambient noise.