TOWARDS VIRTUAL CERTIFICATION OF A COMPOSITE AIRCRAFT MOVEABLE BY MEANS OF DAMAGE TOLERANCE ASSESSMENT: AN UNCERTAINTY QUANTIFICATION FRAMEWORK FOR LVI

Kurzfassung

AdViCe is a DLR internal project advancing analysis methodologies for virtual certification, using a composite aircraft moveable as a use-case to demonstrate certification by analysis as a means of compliance. One of the certification scenarios considered is damage tolerance, specifically the residual strength after barely visible impact damage. While considerable progress has been made in the simulation of low-velocity impact (LVI) and post-impact residual strength, quantifying the predictive accuracy of these methods and propagating the associated uncertainties remains a challenge. The present paper introduces a non-intrusive stochastic finite element framework built around a meso-scale LVI model that combines continuum damage mechanics and cohesive zone modelling. Spatial variability of material properties is represented by Karhunen-Loève-based random fields whose statistical descriptors are derived from literature or from physics-informed analyses of microstructural data. Preliminary results on a CAI coupon, with the mode-II interlaminar fracture toughness as the only stochastic input, demonstrate that spatial material variability produces a clear scatter of the projected delamination area at constant impact energy and supports the relevance of incorporating such variability in LVI simulations. Future work will address the effect of delamination on residual strength, as well as the verification and validation against experimental campaigns.