变截面杆中纵波传播特性的实验研究

Experimental Study of Longitudinal Wave Propagation in Rod with Variable Cross-Section

以往的理论研究结果表明,泊松效应和剪切变形对杆件中纵波的传播特性有着不可忽略的影响,纵波的传播特性也与杆件两端横截面面积比值的大小相关。为了对理论进行验证,搭建了实验系统并进行相关实验。实验结果表明:杆件材料的泊松效应、剪切变形使杆的截止频率变大;同时,变截面杆端面面积比值越大,截止频率越高。实验结果验证了以往的理论预测结果,帮助获取真实的振源振动信号,同时也为状态监测和降噪提供依据。

Previous theoretical studies indicate that the influence of Poisson′s ratio and shear deformation on the propagation characteristics of the longitudinal wave cannot be neglected,and the area ratio between the two ends of a rod may also affect the propagation characteristics.Here,an experimental system is designed,and corresponding experiments are performed in order to verify the theoretical study.A good agreement between the experimental results and theoretical predictions is obtained,i.e.for the present rod with variable cross-section,the Poisson′s ratio and shear deformation led to a higher cut-off frequency,and a higher area ratio between the two ends of the rod also resulted in a higher cut-off frequency.The conclusion contributes to our understanding of real vibration signals and provides a foundation for condition monitoring and noise control.