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.