Efficient modelling and accurate analysis of the dynamic behaviour of a Hi-Lok fastened structure

The use of Hi-Lok fasteners in aircraft structure assemblies is widespread and crucial, necessitating accurate and computationally efficient modelling technique to analyse their dynamic behaviour. This study proposes and evaluates finite element (FE) modelling techniques specifically tailored to Hi-Lok fasteners, aimed at representing and investigating the dynamic behaviour of a physical Hi-Lok fastened structure in terms of natural frequencies and mode shapes. Four distinct techniques, each employing different FE representations, are created using MSC Software packages to represent the physical structure. The predicted dynamic behaviour obtained from the four FE models are systematically evaluated with experimental modal analysis (EMA) counterparts with respect to natural frequency discrepancies, computing time, and disk storage requirements. The evaluation demonstrates that Technique 4, which uses simplified one-dimensional beam representations of Hi-Lok fasteners, accurately predicts the dynamic behaviour of the physical structure with 98.4% accuracy, while maintaining low computational speed and the lowest disk space consumption among the approaches investigated. This validated modelling strategy proposed in this study therefore offers practical guidance for researchers and engineers seeking to efficiently and accurately predict the dynamic behaviour of aircraft structures incorporating Hi-Lok fasteners.