Sandwich shield subjected to bird impact: Use of surrogate models for influencing parameter analysis and shield behaviour understanding

In this work, the behaviour of a sandwich shield subjected to a 1.82 kg bird impact at 175 m/s is studied using a finite element model. The 6 most influential design parameters are varied and their effects on the shield behaviour and on the target protection are assessed. First, we try to establish an engineer's visualization by varying parameters 2 × 2 using three 5-levels full-factorial design of experiments. These three 2D design of experiments enable us to visualize precisely the different effects of each parameter. Then a full sensitivity analysis (6D) is performed using a Latin Hypercube sampling to assess the possible interactions between parameters. Surrogate models are constructed using the Gaussian Process framework to follow the variation of the outputs in the 6D design space. These surrogate models are finally studied using two statistical methods: the Sobol′ method and the Morris method. The methodology developed in this study enables to improve the understanding of the behaviour of a shield under a soft body impact, as a first step towards a shield design tool.