Buckling and postbuckling behaviour of Glare laminates containing splices and doublers. Part 2: Numerical modelling

A 3D finite element model using cohesive elements and continuum (bulk) material damage models was developed to examine the progressive damage and failure behaviour of Glare® Fibre Metal Laminate (FML) specimens subjected to in-plane compressive loading. The specimens contained internal ‘splice’ and ‘doubler’ features and were either pristine or contained simulated manufacturing defects in the form of artificial delaminations. The initiation and growth of delaminations at the inter-laminar interfaces, damage in the glass fibre reinforced polymer (GFRP) plies, ductile damage in the resin pockets (FM94 epoxy) and the onset of plasticity in the metal layers were examined. Geometric imperfections and load eccentricity were incorporated in an explicit dynamic nonlinear analysis implemented in the software Abaqus/Explicit. A series of buckling tests on specimens with and without artificial delaminations were conducted for validation, which are described in detail in a companion paper. Tests were monitored using Digital Image Correlation (DIC) for visualisation of full-field displacements and strains whilst Acoustic Emission (AE) monitoring enabled detection and localisation of the onset and progression of damage. Results for ‘Glare 4B’ specimens incorporating longitudinal and transverse delaminations into both splice and doubler geometries are presented. These results revealed that in order for the finite element analyses to be validated, all the damage and plasticity mechanisms described above need to be accounted for, as well as load eccentricity and geometry imperfections.