Manufacturing signature and operating conditions for tolerance analysis

Many models for tolerance analysis of rigid parts exist in the literature. However, they do not consider the signature due manufacturing processes and operating conditions, such as the presence of gravity, friction and other factors. In this work, the effect of a manufacturing process on solving a stack-up function is investigated for a circular profile obtained by turning. A geometric tolerance analysis has been carried out by simulating two circular profiles manufactured through a turning process and by geometrically assembling them inside a hollow rectangular box in presence of gravity and friction among the parts. This geometrical model should numerically reproduce what happens in the actual assembling, therefore, this model is considered as a reference case. Three further cases have been developed and compared with the reference one. The first is the same geometrical model without the manufacturing signature. The second and the third ones involve an analysis of tolerances carried out by means of a variational model respectively with and without considering the manufacturing signature. This work aims to be a first step towards a tolerance analysis approach able to integrate design and manufacturing in a concurrent engineering approach.