A computational investigation into the impact resistance of a precise finite element model derived from micro-CT data of a woodpecker's head.

Numerical investigation into the impact-resistance of complex biological organs remains challenging because of the difficulties in obtaining accurate models and precise material properties. In this work, the elegance of a woodpecker's head, including a slender hyoid connected by a spherical hinge and two revolute hinges, a long upper beak, a short lower beak, and an encephalocoele filled with viscoelastic brain substances, was obtained via a reaction-diffusion based imaging process on the micro-CT data. The material heterogeneity was fully considered in subsequent finite element analysis in LS-Dyna via categorizing the intensity into 53 groups and interpolating their properties from available data of rhamphotheca, hyoid, skull, and beak. Compared to a non-hyoid model, we found the hyoid helps to significantly alleviate the strain in the brain and restrain opposite velocity for maintaining structural stability, especially after impact. Numerical investigation also indicates that a longer upper beak is favorable in flatting the curve of impact force and improve structural crashworthiness.