MODELING OF HIGH-VELOCITY IMPACT BEHAVIOUR OF SANDWICH STRUCTURES UNDER BIRD STRIKE LOADING

Polyvinyl Chloride (PVC) foam-core based sandwiches with fibre-reinforced composite face sheets provide high strength and bending stiffness as well as good designability, which has been widely used in the manufacturing of transportation vehicles. While these sandwich composite structures may expose to bird strike during the service, which threatens the safety operation of high-speed transportation vehicles. The present studies combine experimental and numerical investigations on the bird-strike resistance of large-size foam-core sandwich composite structures. Gas-gun tests have been carried out to study the behaviours of foam-core sandwich composite structures subjected to an impact by gelatine projectiles. A high-speed camera is employed to capture the deformation of the projectiles and strain gauges are employed to measure the local strain near to the striking point from the rear surface of the specimens. A Finite Element (FE) model is developed to simulate the gelatine-impact on the foam-core sandwich composite structures. The constitutive model of the gelatine is built up using the Smooth Particle Hydrodynamic (SPH) method with the Murnaghan Equation Of State (EOS) for solid element. Foam-core material is modelled using the crushable foam model with isotropic hardening. Regarding the model for composite panel, an in-house subroutine has been employed, which takes account for the strain rate dependency as well as different failure modes. The Finite Element (FE) predicted deformations are compared with the ones experimentally measured by Digital Image Correlation (DIC). Good agreement has been obtained between the Finite Element (FE) predictions and experimental results. The dynamic responses and failure characteristics of the foam-core sandwich composite structures are further studied using the validated numerical model. This piece of work is able to proved some guidance to the design of the bird-strike resistant foam-core sandwich composite structures.