Compliant assembly variation analysis of aeronautical panels using unified substructures with consideration of identical parts

The assembly process of aeronautical panel usually involves numerous parts and subprocesses. Thus a large number of Finite Element Analysis (FEA) runs are required to construct its compliant Deviation Propagation Model (DPM), when using the traditional compliant assembly variation analysis methods such as the Method of Influence Coefficients and the Linear Contact method. In this paper, an efficient DPM construction method based on substructures is proposed to reduce the modeling complexity. Finite element models of compliant parts are condensed into substructures which have relatively fewer Degrees of Freedom (DOFs). And for the identical parts commonly used in the aeronautical panels, once the substructure of one part is generated, the substructures of the others can be obtained by transformation of the generated one. By properly selecting the retained DOFs, the same substructures are applicative throughout the overall modeling process. Based on these unified substructures, the DPM of aeronautical panel assembly process is constructed, without executing extra FEA runs. A case study on a panel subassembly of the side fuselage is used to illustrate the proposed method. The results show that, this method reduces the model size as well as the model construction work, while maintaining the same accuracy as complete finite element analysis conducted in a commercial software package.