Variation Analysis of Three Dimensional non-rigid Assemblies

Variation analysis methods are, currently, more widely used during new product development to greatly reduce downstream rework and/or design changes. This is significantly important when considering large, built up sheet or thin plate "flexible" assemblies as those currently used in automotive or aerospace industries. Whereas methods to take flexibility into account can be found in literature, there are few addressing detailed process for three-dimensional assembly of industrial complexity. This paper presents a streamlined procedure for variation analysis of a complex assembly that integrates Datum Flow Chain analysis, a commercial three-dimensional variation analysis and FEA. The procedure is applied to a realistic industry case, a commercial airplane's wing-box assembly to determine the effect of part variation and flexibility on the assembly's variation. The case study shows that a structural enclosure such as the wing-box assembly is robust against pull-up forces applied during assembly operations.