Numerical modelling of impact and damage tolerance in aerospace composite structures

This chapter discusses numerical methods that are used for predicting impact damage in advanced composite structures. To support the acceptance by industry for design and certification of composite aircraft structures, composites damage models are required for implementation in commercial finite element (FE) codes and validation at specimen and substructure level. DLR experience on modelling damage progression and failure in composite structures under impact is reviewed based on meso-scale composites ply damage models and an energy-based delamination failure criteria in explicit FE codes. The numerical methods are applied to predict impact damage and damage tolerance in stiffened and unstiffened aircraft panels from hard and soft body impacts, including pre-stressed panels subjected to impact loads. Issues concerned with validation of computational methods for certification by analysis are discussed