Acoustic–structure modeling and analysis of an engineering machinery cab based on the hybrid method and experimental investigations

To study the mid-frequency acoustic–structure in the cab of construction machinery vehicle, a prediction model was established based on the FE–SEA hybrid method. Model parameters, such as the modal density, the internal loss factor and the coupling loss factor of each subsystem, were calculated by the theoretical methods. The sound pressure excitation and vibration excitation of the model obtained through the real vehicle experimental tests and the mid-frequency vibration characteristics of the cab in the frequency range of 100–800 Hz under composite excitation were studied. In order to verify the accuracy of the hybrid model, the full FE acoustic–structure coupling model of the cab was also established, and the modal calculation of the cab was carried out. In the end, the two methods were verified by the real sound pressure test in the cab. The results show that the hybrid model has a great deviation from the experimental results in the low-frequency region of 20–80 Hz, and the calculation accuracy is lower than that of the FE model. The prediction accuracy starts to rise when frequency is higher than 80 Hz; especially in the mid-frequency region of 100–800 Hz, the hybrid model accuracy reaches the highest with results basically consistent with the experiment. In addition, in the high-frequency range, higher than 800 Hz, the prediction results also agree well with the experimental ones. It should be pointed out that the hybrid model cannot accurately capture the peak value of the response in the noise prediction, but it can guarantee the accuracy, improve the calculation efficiency and improve the prediction accuracy in the mid-frequency region.