摘要
为了定量评估螺栓松动损伤程度,依据统计学中的马氏平方距离(Squared Mahalanobis Distance,MD)异常值分析法,研究了综合利用结构前5阶固有频率(称为固有频率矢量)检测螺栓拧紧力的方法。首先测试了不同拧紧力下结构的固有频率;然后计算了各拧紧力工况与紧固工况固有频率矢量间的标准欧几里德距离(Standard Euclidean Distance,SED),利用Matlab拟合了SED与拧紧力之间的关系曲线,据此提出了定量检测螺栓拧紧力的方法;最后对该方法进行了试验验证和应用举例。结果表明,固有频率矢量的SED与拧紧力呈指数关系,而且利用此关系曲线能够比较可靠地评估螺栓松动程度。
In order to evaluate the severity of bolt looseness quantitatively,a study was made to detect bolt tightening force using structural first 5 natural frequencies and the squared mahalanobis distance（ MD） outlier analysis.Firstly,the structural natural frequencies under different tightening force condition were measured,and then,the standard euclidean distances（ SEDs） between the natural frequency vector under fully-tightening condition and those under several not-fully-tightening conditions were calculated. The fitting curve for SEDs and tightening forces was made using Matlab,and a method was proposed to detect tightening force. Test verification and application examples were given at last. The results showed that there is an exponential relationship between SEDs and tightening forces,this relationship can be used to evaluate the severity of bolt looseness reliably.
出处
《振动与冲击》
EI
CSCD
北大核心
2015年第23期77-82,共6页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(11090334
11372154)
关键词
螺栓松动
损伤检测
结构健康监测
固有频率
异常值分析
标准欧几里德距离
bolt looseness
damage detection
structural health monitoring（SHM）
natural frequency
outlier analysis
standard euclidean distance
