Geometry robustness evaluation for common parts in platform architecture

Artikel i vetenskaplig tidskrift, 2011

In this paper, a platform geometrical sensitivity value for a part has been defined. Calculation and simulation methods have been defined and tested to be used in industrial “real-life” environments. Present calculation and simulation methods for assembly analysis in a single product development have been used as a basis. These methods have been further developed and adapted to suit product family development, or platforms. The assembly geometrical sensitivity value can be used to predict the effect of tolerance stacking without having data of tolerance sizes available. Using sensitivity calculation in each assembly step gives an indication of the risk of functional failure and non-fulfilled specifications due to tolerance stacking. The platform geometrical sensitivity value could be used for optimization of a part or an assembly, by means of geometric variation, not only for one product environment but also for a complete product family simultaneously. This decreases the risk of sub-optimization of part location and assembly concepts. Using the platform geometrical sensitivity value, the effect of tolerance stacking could be predicted for all assemblies conceptually and the result can be used to dimension specific part tolerances. All equations and mathematical connections are described in detail in the paper but, due to the mathematical complexity of 3D modeling, the calculations have been performed in a geometry simulation tool. Further research needs to be done to establish a proper working procedure using platform geometrical sensitivity value.