Establishment Of The CAD Model And Simulation Research On The Dynamic Characteristic Based On A Certain Passenger Car

With the development of the scientific technology and social economy, people raise higher demand for the safety, riding comfort, environmental friendliness and dynamic characteristic of the passenger bus.The modern design of the car body has already turned from early static analysis to modal and dynamic analysis, because the practical strength of the car body more depends on the whole vehicle vibration and random load response.Research on the vibration of the whole vehicle can preliminarily evaluate the dynamic characteristic and also analyze the possible reasons for resonance so as to avoid them during the design. Studying on the dynamic response to the bus structure under the random road excitation can accurately predict the reliability and life of the bus body frame.This paper used a certain type of passenger bus as the research object, which is one of the Venice Series developed by Nanjing IVECO MOTOR COMPANY LTD. The main works are as follows:(1)The bus body frame as well as the bus frame of a certain passenger bus is established based on Pro/E so as to assemble to a whole vehicle model. The global interference examination should be carried out to eliminate or modify the interference area of the bus body frame.(2)The solid models are turned to the surface models by means of the method of extracting mid-surface. The finite element model of the bus body frame is built based on the shell element.(3)Based on the theory of the structural dynamics , the free modal analysis is performed by means of ANSYS Workbench in order to assess its lower-order frequencies according to the evaluating principle. The result can be used to improve the design of the bus body.(4)The pre-stressed modal analysis is supposed to carried out to combine its results with an existing spectrum to execute random vibration analysis. It calculates the stress distribution and the displacement, velocity and acceleration of the maximum displacement points of the bus body frame under the conditions of inputting two different types of road spectrum. Finally, this paper analyzes the dynamic response of the bus body frame under the action of the random load.