Mechanical Performance of Cranial Bone in Impact Protection of Woodpecker Brain：A Finite Element Study

Human head impact injuries caused by a sudden impact force are very common in aviation lifesaving,car crash accident,war or sports activities. Yet,an intriguing example of nature is woodpecker which is free from head injury even it drums trunk continually at a speed of about 6-7 m/s and a deceleration of about 1000 g.Woodpecker must have special characteristics to attenuate repetitive impact force to sustain rapid pecking without brain injury. In this study,the effect of mechanical property of cranial bone on the brain during impact was investigated using the finite element（FE）approach. It was demonstrated that the pressure,Von-Mises stresses and shear stress at the same point on the posterior of woodpecker＇s brain were decreased greatly compared with hoopoe and lark. It was stated that the higher strength of woodpecker＇s cranial bone might play an important role for preventing woodpecker＇s head injury.