Indexed by:Journal Papers

Date of Publication:2020-06-01

Journal:AIP ADVANCES

Included Journals:SCIE

Volume:10

Issue:6

Abstract:Head injury has become a threat to human life in transportation accidents, construction. and sports. However, woodpeckers can avoid injuring their brain during high velocity and frequency pecking. To reveal the underlying secret, the pecking process of woodpeckers is simulated and compared with that of chickens and pigeons to study the stress wave propagation in their head. The pecking data of live chickens and pigeons are simultaneously obtained from the force sensor and the high-speed video system. The morphological information of the three birds' heads is also investigated using Micro Computed Tomography (Micro-CT) scanning. The results show that the woodpecker has the highest skull volume fraction and beak length fraction, which could potentially increase its head structural strength and provide more space to dissipate impact stress. The finite element head models of the woodpecker, chicken, and pigeon are established based on the micro-CT images and performed pecking process simulations. The simulated results suggest that the stress wave propagates through both the upper-beak and lower-beak of the woodpecker to ensure the enough structural strength in order to overcome the fierce impact. On the other hand, the structural strength requirement of the chicken and pigeon is not as high as the woodpecker due to their lower pecking intensity. Setting the stouter lower-beak of the chicken and the pigeon as the primary wave propagation path not only ensures their head safety but also avoids direct impact to their brain. The biomechanical design of the bird's heads, setting a special propagation path for the stress wave, may inspire new approaches to improve and design impact resistance equipment.