一种悬臂梁模态测试方法1)

基于欧拉-伯努利梁理论得到悬臂梁自由振动的振型函数。通过数值计算得出实验用的悬臂梁前五阶振型的节点位置及其与梁长的比值。考虑传感器对悬臂梁固有频率的影响,建立梁-传感器模型进行仿真分析并得出悬臂梁前五阶固有频率。基于节点位置和测点位置,在实验中选择激励点。将具体实验的结果与梁-传感器仿真模型结果进行对比,通过前五阶固有频率的误差分析,发现仿真分析结果与实验结果误差最高为 1.3%。研究完整地叙述了悬臂梁的模态测试流程,可为工程技术人员的模态测试起一定的指导作用。

A MODAL TESTING METHOD FOR CANTILEVER BEAM1)

Based on the Euler-Bernoulli beam theory, the modal function of the free vibration of the cantilever beam is obtained. The node position of the first five modes of the cantilever beam and its ratio to the length of the beam are obtained by the numerical calculation. With the consideration of the influence of the sensor on the natural frequency of the cantilever beam, a beam-sensor model is established to simulate and analyze the first five natural frequencies of the cantilever beam. Based on the locations of the nodes and the measuring points, the excitation points are selected in the experiment. The experimental results are compared with the results of the beam-sensor simulation model. Through the error analysis of the first five natural frequencies, it is found that the maximum error between the simulation results and the experimental results is 1.3%. The details of the modal testing process of the cantilever beam are described in this paper.