In the aerospace field, the rigid-flexible coupled structure is widely used due to its high structural efficiency. However, the existence of the rigid-flexible coupling effect poses a significant challenge to active vibration control. To address this issue, this paper takes the three-flexible beam coupling system as the research object and conducts active vibration control research. During the investigation, first, a vibration measurement and control platform for a three-flexible beam coupling system was established, and piezoelectric sensors and actuators were used to detect and suppress the vibration signals. Based on this, vibration measurement and control algorithm design were carried out. Subsequently, the system dynamics model was established by combining the finite element method with the Hamilton variational principle. The main modal shapes of the system’s free vibration in the simulation environment were determined, and the modal coordinates were introduced to obtain the state space equations of the system. At the same time, considering the uncertainty of model parameters, wavelet analysis and jump spider optimization algorithm were used to accurately identify the parameters of the system state space equations. In addition, considering the nonlinearity and parameter uncertainty of the system, a fuzzy logic controller based on Gaussian membership function was designed to suppress the vibration of the flexible beams. Simulated and experimental results show that, within the same control saturation voltage period, the fuzzy logic controller performs better than the large-gain PD (Proportional and Derivative) control in suppressing the vibration of the three-flexible beam coupling system. It can suppress the large-amplitude vibration quickly while suppressing the small-amplitude vibration at a faster speed, effectively shortening the time for the system to reach a stable state and significantly improving the vibration control effect. In summary, the fuzzy logic controller based on Gaussian membership function designed in this paper overcomes the nonlinearity and parameter uncertainty in the vibration control of rigid-flexible coupling structures, and shows stronger adaptability and higher control efficiency than the traditional large-gain PD control.

In order to effectively calculate the fatigue life of rubber vibration isolator under random vibration loads, a rubber vibration isolator for air conditioning compressor of an electric vehicle was taken as the research object, and the road spectrum acquisition of rubber vibration isolator was carried out, by which the acceleration signals versus time of rubber vibration isolator were obtained. Then, Fourier transform was used to transform the acceleration signals into the acceleration power spectral density as load input, and a random vibration test of rubber vibration isolator for compressor was carried out under variable temperature and constant humidity conditions, with the cracking of main spring of rubber vibration isolator being observed. Moreover, a finite element model of rubber vibration isolator was established, with its validity being verified by static characteristic tests as the relative error between simulation value and test value is within ±5%. In addition, frequency response of rubber vibration isolator under unit load was analyzed by ABAQUS, that is, extracting and importing stress response PSD of rubber element into Fe-safe, and using acceleration PSD as load input to calculate the fatigue life. The calculated results were compared with the random vibration test results, finding that the predicted life is consistent with test data, with a relative error of only 2. 5%, and that fatigue danger position of rubber vibration isolator unit can be effectively predicted. Finally, the structure of rubber vibration isolator was improved, through which the fatigue life of rubber vibration isolator is 2. 8 times that before the improvement, meaning that the fatigue life design requirements are successfully met. This study helps to shorten the design cycle of rubber vibration isolator and reduce the cost of sample test.