Phase Field Simulation of Laminated Glass Beam

The complex failure mechanisms of glass laminates under in-plane loading conditions is modelled within the framework of phase-field strategy. Laminated glass is widely used for structural purposes due to its safe post-glass-breakage response. In fact, the combination of several glass plies bonded together with polymeric interlayers allows overcoming the brittleness of the glass and to reach a pseudo-ductile response. Moreover, the post-breakage behaviour of the laminate is strictly correlated by the mechanical properties of the constituents. Ruptures may appear as cracks within the layers or delamination of the bonding interface. The global response of a glass laminate, validated against experimental results taken from the literature, is carried out by investigating a simplified layup of two glass plies connected by cohesive interfaces through an interlayer. Delamination of the adhesive interface is described, and crack patterns within the materials are fully described. Finally, the proposed approach put the basis for future comparisons with results of experimental campaign and real-life applications.

A Moving Interface Finite Element Formulation to Predict Dynamic Edge Debonding in FRP-Strengthened Concrete Beams in Service Conditions

A new methodology to predict interfacial debonding phenomena in fibre-reinforced polymer (FRP) concrete beams in the serviceability load condition is proposed. The numerical model, formulated in a bi-dimensional context, incorporates moving mesh modelling of cohesive interfaces in order to simulate crack initiation and propagation between concrete and FRP strengthening. Interface elements are used to predict debonding mechanisms. The concrete beams, as well as the FRP strengthening, follow a one-dimensional model based on Timoshenko beam kinematics theory, whereas the adhesive layer is simulated by using a 2D plane stress formulation. The implementation, which is developed in the framework of a finite element (FE) formulation, as well as the solution scheme and a numerical case study are presented.

Interface Failure of Heated GLARETM Fiber–Metal Laminates under Bird Strike

Many high-strength composite materials have been developed for aircraft structures. GLAss fiber REinforced aluminum (GLARE) is one of the high-performance composites. The review of articles, however, yielded no study on the impact damage of heated GLARE laminates. This study, therefore, aimed at developing a numerical model that can delineate the continuum damage of GLARE 5A-3/2-0.3 laminates at elevated temperatures. In the first stage, the inter-laminar interface failure of heated GLARE laminate had been investigated at room temperature and 80 °C. The numerical analysis employed a three-dimensional GLARE 5A-3/2-0.3 model that accommodated volumetric cohesive interfaces between mating material layers. Lagrangian smoothed particles populated the projectile. The model considered the degradation of tensile and shear modulus of glass fiber reinforced epoxy (GF/EP) at 80 °C, while incorporated temperature-dependent critical strain energy release rate of cohesive interfaces. When coupled with the material particulars, an 82 m/s bird impact at room temperature exhibited delamination first in the GF/EP 90°/0° interface farthest from the impacted side. Keeping the impact velocity, interface failure propagated at a slower rate at 80 °C than that at room temperature, which was in agreement with the impact damage determined in the experiments. The outcomes of this study will help optimize a GLARE laminate based on the anti-icing temperature of aircraft.