CAE Of Bus Structure Dynamic Performance And Interior Structure-radiated Sound Field

According to the requirements for solving the flaws on dynamic performance of the whole bus structure and reducing bus interior noise, the paper uses CAE technique to analyze the whole bus structure dynamic performance and interior structure-radiated sound field for the bus under the engine excitations. The main contents and conclusions are as follows:(1)Introduce the conception, characteristics and flow of CAE technique, the principles of dynamic analysis including modal analysis, harmonic analysis and spectrum analysis, and the theory of FEM and BEM used in calculating the bus interior sound field.(2)Go to particulars on process of building model of the whole bus structure for dynamic performance analysis, and discuss the procedure, approaches and some key problems in building a system-level FEM model of a bus.(3)Carry out a system-level modal analysis for the whole bus structure. According the results, make some evaluations on the dynamic performance of the bus, and find out reasons why the bus resonates at idle as well.(4) Carry out a harmonic analysis for the whole bus structure with excitations of engine. Also make some evaluations on the dynamic performance of the bus when it's excited by engine vibrations. From the analysis result, a resolution of the resonance problem is obtained.(5)By putting the actual excitation spectrums of engine that get from testing into the bus model, a spectrum analysis is performed. By contrasting the vibration responses of the structure from calculation with that from testing, the reasonableness of the bus model is then testified.(6)Build FEM and BEM model of the bus interior acoustic cavity. Then, calculate the acoustic modes, and get the information of natural characteristics of the bus interior acoustic cavity. After that, two analysis methods FEM and BEM are separately used to calculate the bus interior sound field (20~200Hz) that generated by the bus panels' vibrations originated from engine excitations. At last, sound field results calculated by FEM and BEM are compared and the foundational analysis for the bus interior acoustic characteristics are made.