基于压电材料的钢筋砼-钢组合塔筒损伤监测

钢筋混凝土-钢组合塔筒作为一种新型的风电塔架形式,其混凝土段的开裂对其使用寿命具有重要影响,对其混凝土段的开裂进行监测具有重要意义。该文提出了一种基于压电陶瓷激励的应力波测量的钢筋混凝土塔段的开裂监测方法,以某钢筋混凝土-钢塔筒缩尺模型为对象,以布置在钢筋混凝土塔筒表面的压电陶瓷片为激励器,利用布置在钢筋混凝土塔筒不同高度位置的压电陶瓷片作为传感器,实现在不同水平往复加载下的应力波的测量。对混凝土塔段从裂缝开始出现直至构件最终破坏整个过程各压电陶瓷片的响应进行分析,并定义损伤指标。结果表明,定义的指标不仅可较好反应裂缝实际出现位置,且与加载等级相关,所提出的监测方法可对钢筋混凝土塔段裂缝的发生和发展过程进行有效监测。

Damage Detection of a Reinforced Concrete-Steel Hybrid Wind Turbine Tower Model With PZT

The reinforced concrete-steel hybrid wind turbine tower is a new type of wind turbine structure. The initiation of cracks in concrete has obvious influence on the durability of the wind turbine tower and it is critical to monitor the initiation and development of cracks in concrete of the hybrid tower. In this paper, a PZT based stress wave propagation measurement and analysis method for the crack initiation and propagation monitoring is proposed. The experimental study on the crack initiation and propagation monitoring for a scale reinforced concrete-steel hybrid tower model is carried out. A number of PZT patches are mounted on the surface of the concrete tower and some of them are used as actuator and the others are used as sensors for stress wave measurement. The high frequency sine signal from a signal generator is used to actuate the PZT actuator and the stress wave is measured by different sensors under different load cases. A damage index based on the amplitude is defined and it can be employed to detect the location of the cracks in the concrete tower and changes with the development of cracks. The proposed approach can be employed to monitor the cracks in concrete-steel hybrid wind turbine tower.