Effect of Flexible-Body Assembly Errors on Appearance Quality of Automotive Bodies

The appearance quality of automotive bodies is among the features which are, in recent years, significantly taken into consideration by designers throughout the world. Automotive bodies are, to a great extent, constructed from flexible sheet metal components and would deform and distorted easily by even a slight assembly force. Therefore, errors due to manufacture and assembly processes of automotive bodies lead to major deviation from the ideal product and finally affect the appearance quality and cosmetic features of the vehicle. The effect of these errors, which are commonly arisen by dimensional, geometric or assembly tolerance of the components, can be examined by tolerance analysis. As one of the key quality characteristics in vehicle design, this paper evaluates the appearance quality of automotive bodies as a function of assembly derived errors. In the proposed methodology, by means of the nonlinear finite element analysis and by presenting the surface interrogation techniques, a comprehensive approach of quality appearance evaluation of vehicles is developed. The approach is validated by a vehicle example and the results show a great consistence with practical data obtained from the production line.