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.

中文翻译：

---

与鸡和鸽子相比，啄木鸟在啄食期间如何保护大脑免受脑震荡

头部受伤已成为交通事故，建筑施工中对人类生命的威胁。和运动。但是，啄木鸟可以避免在高速啄食和啄啄频率期间伤害其大脑。为了揭示潜在的秘密，模拟了啄木鸟的啄食过程，并与鸡和鸽子的啄食过程进行了比较，以研究应力波在其头部的传播。可以从力传感器和高速视频系统同时获取活鸡和鸽子的啄食数据。还使用微型计算机断层扫描（Micro-CT）扫描研究了三只鸟的头部的形态信息。结果表明，啄木鸟的颅骨体积分数和喙长分数最高，这有可能增加其头部的结构强度，并为消散冲击应力提供更大的空间。基于微CT图像建立啄木鸟，鸡和鸽子的有限元头部模型，并进行啄食过程模拟。模拟结果表明，应力波通过啄木鸟的上喙和下喙传播，以确保足够的结构强度，从而克服了剧烈的撞击。另一方面，鸡和鸽子的结构强度要求不如啄木鸟高，因为它们的啄木强度较低。将鸡和鸽子的喙下喙设置为主波传播路径，不仅可以确保其头部安全，还可以避免对大脑的直接影响。鸟头的生物力学设计为应力波设置了特殊的传播路径，