More geometric tolerances on the same surface for a variational model

Tolerance analysis studies the accumulation of dimensional and/or geometric variations resulting from a stack-up of dimensions and tolerances. It is the fundamental tool to allocate the tolerances on the single components by solving the trade-off between the quality and the cost of the whole assembly. This work presents how it is possible to deal with more geometric tolerances applied to the same surface, when a tolerance analysis is carried out by means of a variational model. It modifies the expression of the stack-up function in order to deal with all geometrical tolerances, Enveloped and Independent principles. The proposed approach was applied to a case study constituted by three rigid parts. The obtained results show that all the applied geometrical tolerances significantly influences the assembly requirements and, therefore, they should not be ignored in the tolerance analysis of rigid assemblies.