【摘要】 针对螺栓联接状态监测问题,提出了基于压电阻抗解耦技术的螺栓松动监测技术。建立相应的实验装置,检测螺栓在不同预紧力下的导纳信号,将所采集的压电导纳信号,剔除导纳信号的被动部分后对所得到的导纳信号主动部分采用阻抗解耦算法,获得新的测点结构阻抗信息。以解耦得到的测点结构阻抗信号的实部定义了RMSD(Root Mean Square Deviation均方根偏差)损伤指标,识别螺栓联接状态(表现为螺栓轴向预紧力变化)。试验表明:导纳实部损伤指标能反映螺栓的联接状态;将解耦得到的机械阻抗实部作为监测螺栓联接状态的指标,较之常用的直接采用导纳信号实部定义的RMSD损伤指标,该方法所得的损伤指标明显提高,能更加有效的识别螺栓联接状态。更多还原

【Abstract】 For the problem of bolt connection state monitoring,a technique of bolt looseness monitoring based on piezoelectric impedance decoupling technique is proposed. After subtracting the pas sive part of the measured admittance signal from collected piezoelectric admittance signal,the impedance decoupling algorithm is applied to obtain the measured point structure impedance information from the rest of the active part of the signal. The RMSD(Root Mean Square Deviation root mean square deviation)damage index is defined by the real part of the measured point structural impedance signal,and the bolt connection state is identified by RMSD damage index. The experimental results show that the admittance damage index can reflect the bolt connection state. For monitoring bolt connection state index,the real part of mechanical impedance obtained by decoupling is better than admittance signal directly defined by real part of admittance signal. And the method can identify bolt connection status more effectively.更多还原