Tolerance Analysis of Compliant Assemblies Using FEM Simulations and Modal Description of Shape Defects

This paper propose to perform tolerance analysis on compliant structure. The objective is to limit shape defects and connection defects in accordance to mechanical criteria instead of geometrical criteria. The idea is to elaborate a finite element model of the structure and to observe the stress induced by assembling non ideal parts. Firstly, a method to take into account the stiffness variation induced by the shape defects is tested on an elementary example. Secondly this method is applied on an large structure from aeronautical industry with a lot of variability. A method is also presented to find the geometrical defects which are mostly responsible of overloading the connections.