基于振动模态的振动筛横梁裂纹损伤机理

摘要

In this paper,firstly,Ritz-series method based on principles of power balance will be applied in calculations of crack beam and calculate the natural frequency and mode shapes of crack simply supported beam. Secondly,the ANSYS was used to make modal analysis of crack simply supported beam,and to identify it with methods of modal shape and energy density.The modal shape and energy density were combined with BP neural network method in order to make a precise identification of damage location.Finally,an experimental modal analysis was undertaken with crack simply supported beam,and from the test results it could show that crack damage was sensitive to the natural frequency and modal shape,and the overall trends were consistent with theoretical modal analysis.%将基于功率平衡原理的Ritz级数法应用到损伤梁计算中，计算出简支梁损伤前后的固有频率和振型。基于ANSYS有限元对裂纹简支梁进行模态分析，用模态振型和能量密度对裂纹梁的损伤位置做出了精确的识别，并结合 BP 神经网络法对裂纹梁的损伤程度做出了准确的判断。对裂纹简支梁进行试验模态分析，结果表明，裂纹损伤对固有频率和模态振型有一定的敏感性，总体变化趋势也和理论模态分析一致。