Finite Element Analysis in the Characteristics of Ostrich Foot Toenail Traveling on Sand

Abstract

The ostrich foot toenail plays a crucial role in the process of ostrich foot traveling on sand. 3D laser scanner was used to measure the three-dimensional point clouds of ostrich foot toenail surface morphology, and the three-dimensional model of ostrich foot toenail was reconstructed by using reverse engineering technology. The finite element analysis in the interactions between ostrich foot toenail and sand was implemented by Abaqus and Hypermesh. The quasi-static analytical results of ostrich foot toenail inserting the sands showed that the groove structure of the toenail had a better sand fixation effects, the tiptoe structure was conducive to insert into the sands, and the inverted triangular structure of the toenail had the weak disturbance on the sands which produced the less resistance of the toenail inserting the sands. According to the velocity and the stress fields in the process of the ostrich foot toenail dynamically traveling on sand, ostrich foot toenail tiptoe could help to improve the thrust of traveling on sand, the groove area of the toenail played the effects of sand fixation and flow limitation in the process of ostrich foot toenail traveling on sand. Keywords: ostrich foot toenail, reverse engineering, model reconstruction, finite element simulation, sand fixation and flow limitation.

Bionic research on spikes based on the tractive characteristics of ostrich foot toenail

“…During highspeed running, the toenail of the 3rd toe improves the fixed and tractive performances (Figure 2(a)) and therefore is closely related to the ostrich's high-speed and durable running characteristics. 28 The process of toenail insertion into soils is divided into three. Firstly, the inner groove touches the sand, forming obvious bulges below the toenail, and then the range of the stress field maximizes.…”

Drag reduction and wear resistance mechanisms of a bionic shovel by discrete element method simulation

“…9,10 An ostrich foot toenail has four distinct structural regions, namely a plane region, an inner groove region, a back inverted triangle structure, and a side groove region (Figure 1(b)). 11 The process of toenail insertion into soils is divided into three conditions. Firstly, the inner groove touches the sand, and then obvious bulges are formed in below the toenail and the range of stress field maximizes.…”

Macroscopic and microscopic analyses in flexor tendons of the tarsometatarso‐phalangeal joint of ostrich (Struthio camelus) foot with energy storage and shock absorption

“…An adult ostrich can span 3.5 to 7 m every stride, and continuously run at speed of 50–60 km/hr (sprint speed = over 70 km/hr). Ostriches can run up to 30 min without fatigue and thus are the fastest bipedal bird with regard to terrestrial locomotion (Zhang, Liu, Zhang, Zeng, & Li, ). Such high‐speed running is attributed to muscles, tendons, legs, feet, other anatomical structures, and their mutual coordinations (Baciadonna, Zucca, & Tommasi, ; Rubenson, Lloyd, Heliams, Besier, & Fournier, ; Schaller, D'Août, Villa, Herkner, & Aerts, ).…”

“…Therefore, the tarsometatarsus and phalanges are mainly connected by tendons and ligaments (Rankin, Jonas, & Hutchinson, ). During high‐speed ostrich running, the foot is regarded as the main actuator for ostriches (Schaller et al, ; Zhang et al, ), and the internal tendons play a significant role in force transmission to drive the tarsometatarsus and toe locomotion. As a connective joint, TMTPJ is permanently elevated above the ground plane (Schaller et al, ) and is critical in energy storage and shock absorption between touch‐down and lift‐off of the foot (Zhang et al, ).…”