Vibration Comfort Analysis Under Road Excitation And Optimization Of Body-In-White

With the advancement of science and technology and the increasing standard of people’s life, automobile sales volume and the inventory of our country are presenting the tendency of rapid growth. People not only pay attention to the price and security of automobile, but also pay more and more attention to the automobile comfort when they intend to purchase automobile. Body’s vibration is the key aspect in the whole vibration transfer path, so the research of vibration comfort in terms of body structure seems very important, and it has high practical value for body structure design.In this article, a new method which combines the finite element method with multiple-body dynamics was introduced to study the automobile vibration comfort with rough road excitation and the optimization of body structure design based on the vibration comfort. The multiple-body dynamics model of tires and suspension and finite element model of body structure were established according to a local and independent car model. The body’s response in multiple-body dynamics model under B level rough road excitation was taken as the input for finite element model of body structure. Then the analysis on the vibration of body parts under rough road excitation was made by means of finite element method. The mechanism of how body structure influences automobile vibration comfort was analyzed. The acceleration of driver’s seat was used to evaluate automobile vibration comfort according to the national evaluation method for vibration comfort. The sensibility of body parts to vibration comfort was analyzed and the key parts were found. Further analysis was made in order to enhance vibration comfort by means of thickness and stiffening rib optimization on those key parts. The results show that body parts have remarkable influence on vibration comfort. The vibration comfort can be improved greatly by body structure optimization by changing the thickness and adding appropriate stiffening ribs. This method will prove to be useful for future automobile body structure optimization design.