三自由度载人离心机弹性边界下的模态测试研究OACSTPCD

Objective To explore the modal testing method for the three-axis manned centrifuge under elastic boundary conditions with considerations on its complicated structure and high rotational inertia.Methods Modal testing was carried out with a three-axis manned centrifuge under elastic boundary conditions as the subject and a force hammer as the excitation source according to GJB 2706A-2008 Modal tests method for spacecraft and GB/T 11349.3-1992 Experimental determination of mechnical mobility measurements using impact excitation.Four times of hammering were carried out at each excitation position,and the data of the four times of hammering underwent linear average computation.Data acquisition was implemented with a three-axis accelerometer and a 64-channel data collector,and the modal data were analyzed using a frequency response function based on the Test.Lab modal test and analysis software.Results The coherence coefficient of the excitation signal was not lower than 0.8 in the 30 Hz band;the first three orders of the system's intrinsic vibrations were all torsional vibrations,with the frequencies of 9.15,15.66 and 19.22 Hz,respectively;the first order frequency of the system was about 9.15 Hz for both Z18 and Z21 excitation positions,and each of the second and third order frequencies similar situations were observed for also had a roughly equal value for the two excitation positions.Conclusion The force hammer testing method is applicable for the modal testing of the three-axis manned centrifuge,ensuring equipment safety and subject comfort.Referen-ces are provided for the following structural optimization design.[Chinese Medical Equipment Journal,2024,45(8):38-43]