Surface fairness: a quality metric for aesthetic assessment of compliant automotive bodies

The superior quality of automotive body surfaces is nowadays of growing concern to any customer. Thus, it has been one of the key issues in the car body designing process. The manufacturing tolerances play a crucial role in the quality of products in mass production. With the advances in computer-aided design and engineering (CAD/CAE) software, the tolerance analysis has been taken into detailed consideration for aesthetic assessment of automotive bodies in recent decades. In this paper, the surface fairness has been chosen as a quality metric for the compliant automotive bodies. The relationship between input statistical tolerances and output fairness factor of the assembly has been established by integrating finite element analysis (FEA) with surface interrogation techniques in order to visually assess the quality of products prior to costly manufacturing processes. The proposed methodology is categorised into three main modules: nonlinear FEA, fairness assessment, and statistical analysis. The results of this study, validated by experimental measurements, clearly demonstrate that input tolerances exert powerful effects on the quality of surfaces and, hence, the aesthetic characteristics of the final assembled products.