Refined Bird Model Considering Soft and Skeletal Tissues for Bird Impact Simulation

Abstract

To more accurately characterize the load characteristics of birds under the impact of aviation structures, this study conducted computed tomography scanning of a 1-kg chicken and proposed a geometric model of the bird, including bones, muscles, viscera, and cavities. The constitutive model of fluid dynamics was used to describe the rheological properties of muscle viscera, and a bilinear follow-up plastic model with failure was proposed to describe the mechanical behavior of bones under high-speed impact, and then the bone and muscle/viscera models were assembled into a refined bird model to establish a finite element model. The model was verified with bird impact testing on a rigid target. By comparing and analyzing the impact pressure with the traditional bird model, it was found that the initial impact pressure and stagnation flow pressure of the CT scan refined bird model were lower than those of the traditional bird model and were close to the experimental values. The reason for this phenomenon is that the CT scan refined bird model to some extent reproduces the response of the real structure inside the bird body during the impact process, the high strength level of the bone part model will reduce the material’s movement speed after the bird body model rheological changes, and it well demonstrates the phenomenon of reduced mixing density after rheological deformation during simulation.