【摘要】 针对工程结构中螺栓松动问题,采用万能试验机对螺栓联接结构进行加载模拟螺栓预紧力的变化,在不同螺栓预紧力作用下,测量螺栓联接结构上所安装的压电材料的阻抗变化,利用压电导纳实部均方根偏差(RMSD)对螺栓的松紧程度进行识别;分析损伤指标(RMSD)随预紧力变化的规律和压电材料安装位置及联接结构接触面粗糙度对损伤指标的影响。试验结果表明:在不同频率段和不同预紧力的作用下,随着预紧力的增大,损伤指标呈减小的趋势;压电材料的安装位置和接触面粗糙度对损伤指标测量结果均有一定的影响;损伤指标可以较准确地识别螺栓预紧力的变化。更多还原

【Abstract】 For the problem of bolt looseness in the engineering structure,the piezoelectric impedance based method is investigated and applied to detect the bolt looseness status,and the universal testing machine is used to simulate the changes of bolt pre-tightening force on the bolted structure for the experiments. Under different pre-tightening force,the impedance analyzer is utilized to measure the impedance of the PZT( Lead Zirconate Titanate)piezoelectric patches which pasted on the main structure. Exploiting the root mean square deviation( RMSD) value of admittance of the real part,the degree of bolt looseness is identified. The results show that,the damage indicators tended to decrease while the bolt pre-tightening force increase and the change of bolt pre-tightening force could be identified by the RMSD; both the position of PZT and the roughness of contact surface have certain influences on the results of damage indicator.更多还原