【摘要】 文中由应力强度因子导出含裂纹单元的刚度矩阵,从而提出了一种有限元法.将该法用于单边裂纹悬臂梁,计算了应变响应.用时域法识别了模态参数,并考虑了裂纹闭合的影响.分析了应变响应对故障的敏感度,计算结果表明,应变响应相对于位移响应而言,对故障更敏感.本文还提出了一种判别函数,该函数对于损伤检测,比现有几种判别函数更有效.最后,给出了一种在线振动监测与故障诊断新方法.更多还原

【Abstract】 This paper presents a finite element method by deriving the stiffness matrix of cracked element from the stress intensty factor. The method can be applied to evaluate the strain response of a cantilever beam with single edge crack. By using the method of identification in time domain, the modal parameters are identifiedand at the same time the effect of crack closure is taken into consideration. An analysis on the sensitivity of the strain to the faults is perfomed. Test results show that the displacement response. The a distinguishing function is introduced, which is more effective than any one of existed in the failure detection. At last, a new approach to on-line vibration monitoring and fault diagnosis is given.更多还原