Methodology for identification of Impact behavior of materials: application to bird strike

This work proposes a methodology for identification of material parameters in the case of bird strike tests. A measure of displacement field of the backside of samples is performed by stereo-correlation of high speed cameras images. Hundreds of images are taken during the impact event, leading to reconstruction of corresponding deformed surfaces. The proposed identification methodology supposes that enough data is collected to identify both material parameters of an aluminum target plate and the ones of gelatin projectile. An error function is computed by comparison of the measured and simulated deformed surfaces. Due to the non-linear dependence of the error function on material parameters, a global optimization approach based on meta-modelling is considered. This methodology enables the direct identification of material parameters at the effective rates of loadings, without the need for lower scale coupon testing which do not always involve the right material and structural behaviors. Once the numerical model of gelatin projectile is identified, this approach could be derived to identification of more complex target material models like composite plates and sandwich structures.