Modelling pre-fatigue, low-velocity impact and post-impact fatigue behaviours of composite helicopter tail structures under multipoint coordinated loading spectrum

This paper aims to numerically study progressive pre-fatigue, low-velocity impact (LVI) and post-impact fatigue (PIF) damage behaviours of a full-scale composite helicopter tail structure under multipoint coordinated loading spectrum. A mixed progressive damage algorithm incorporating residual strength and stiffness degradation rules and failure criteria is developed for progressive fatigue and LVI damage analysis of plain-weave (PW) and unidirectional (UD) composites. Novel global–local​ FE modelling technique is proposed for parallel computation and real-time data transferring of global–local FE models in progressive pre-fatigue, LVI and PIF damage modelling of helicopter composite tail structure. The numerical predictions from this work agree well with experimental data from previous literature, indicating that the mixed algorithm and global–local FE modelling technique can effectively analyse the impact damage tolerance of large full-scale composite aircraft structures.