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以加筋复合材料圆筒结构为对象,研究了复合材料结构的外部低速撞击识别问题。采用压电传感器获取发生低速撞击时在结构内产生的应力波信号。针对加筋复合材料结构的撞击位置识别,特别是监测区域边缘的位置识别问题,提出了基于传感器信号功率的两步法来估计撞击位置;撞击载荷的重构采用系统辨识方法,通过分析系统辨识方法中传递函数的模型阶次和相关性系数的关系,提出了模型阶次选择的原则以进一步完善该方法。结果表明:所提出的两步定位法可较好地估计所有监测区域的撞击位置,所改进的系统辨识方法可较好地识别非加筋区域上的撞击位置和撞击载荷时间历程;当撞击点为加筋区域时,由于筋条对应力波传播的复杂影响导致撞击识别误差偏大。
Taking the reinforced composite cylindrical structure as object, the external low-speed impact recognition of the composite structure was studied. Piezoelectric sensors are used to obtain the stress wave signal generated in the structure when a low-speed impact occurs. Aimed at the collision location recognition of reinforced composite structures, especially on the edge of monitoring area, a two-step method based on sensor signal power is proposed to estimate the impact location. The reconstruction of impact load adopts the method of system identification, The relationship between the model order and the correlation coefficient of the transfer function in the method, the principle of model order selection is proposed to further improve the method. The results show that the proposed two-step localization method can better estimate the impact location of all the monitoring areas. The improved system identification method can better identify the impact location and impact load time history in the non-reinforced area. When the impact point For the reinforced area, due to the complex impact of the rib on the stress wave propagation, the impact recognition error is large.