Aiming at the problem of large vibration in the idle state, the vibration testing and hammering modal experiment were done for 6830CR1 bus. The natural frequency and intrinsic characteristics of the entire bus were obtained. It is found that the main factor influencing the bus vibration is the vibration of chassis beam transmitted from the engine, and this factor is closely related with the idle speed. Through the structural simulation analysis of the chassis and comparison of the result with that of the modal testing, it is determined that the bus vibration is a coupling problem between the idle operating frequency and the natural frequency of the chassis. Finally, the phenomenon of coupling resonance is eliminated by improving the local structure of the chassis.

The noise and vibration of a centrifugal compressor’s piping system in an oxygen company are measured for its abnormal noise studying. The distribution of noise and vibration are obtained and analyzed. The model of piping system is built and simulated by using the statistical energy analysis (SEA) method. The cause of the overnoisy of the piping system is detected. Results of the simulation are essentially in accordance with the measurement data. Therefore, the SEA method is proved to be significant for optimal design and noise monitoring and control of the compressors pipeline system.

A three-dimensional model of finite element method and boundary element method for computing vibration and acoustic radiation from the limited cylindrical pipe shell has been established. The pipe shell’s modes have been analyzed by the finite element modal analysis and experimental modal analysis. The modal analysis results with ANSYS FEM software will be imported into BEM software SYSNOIS, then under the fluid - structure coupling radiation using the software BEM SYSNOISE calculates the pipeline model’s sound radiated power level and studies the different restrictions、thickness and damping for the effects of the pipe vibration and acoustic radiation. Some suggestions which can reduce structural vibration and acoustic radiation are given out.