The identification of failure initiation hotspots in idealised composite material component models using a “bottom-up database” method

Idealisations are inevitable for finite element simulations of complex composite structures especially airframes, where laminates are commonly modelled using shell elements for relatively low computational cost. However, identification of failure initiation locations is crucial in designing airworthy structures, which requires complex models incorporating details to capture damage initiation accurately. This often leads to high computational cost and is only acceptable in sub-models for some local regions of interest. In this work, we present a method for re-using results of detailed models to identify failure initiation hotspots in global models. In the workflow, commonly encountered geometric features are analysed in isolation from complex structures. Unit loads are applied individually to a detailed feature model, wherein stresses at critical points are extracted and stored in a database, which will be later accessed to identify failure initiation hotspots by testing interface loads extracted at feature boundaries of the global model against the developed database. This workflow is demonstrated with an L-shaped clip model. Comments and discussions on modelling errors are also presented regarding the confidence in hotspot location predictions. This approach is considered more efficient than traditional ones for components with a limited number of common features.