Quantitative Modeling and Decoupling Method for Assembly Deformation Analysis Considering Residual Stress from Manufacturing Process

摘要

Nonuniform residual stress inevitably exists in thick asymmetric component because of fabrication history originating from raw material processing. Bulk residual stress distribution of component has an impact on large-scale assembly deformation and consequently affects dimensional and shape accuracy of assembly. This paper illustrates a simulated method of introducing a component's bulk stress state with corresponding overall deformation after machining as input to assembly analysis and decoupling the assembly deformation induced by residual stress factor through comparison quantitatively. The differences of theoretical formulating and physical meaning are discussed with the traditional method of influence coefficient (MIC) and assembly thermal expansion issue, respectively. The main procedure of potential bulk residual stress quantification for a component's material is described involving surface stress measurement and numerical finite element analysis (FEA) processing based on normalized stress distribution shape and regression relation of key stress points. The comprehensive methodology is tested in validation experiments. The results show that the prediction compared with observation is acceptable within a certain range of error in view of uncertainties. A practical engineering case, the rear spar structure composed of edge components in horizontal stabilizer assembly, highlights the necessity of incorporating residual stress factor during further assembly analysis. The investigations of this research enhance the understanding of the effect of residual stress and help systematically improve compliant assembly precision in aircraft (C) 2014 American Society of Civil Engineers.