This paper aims to reveal the multi-optimal mechanisms for dynamic control in drag- onfly wings. By combining the Arnold circulation with such micro/nano structures as the hollow inside constructions of the pterostigm...This paper aims to reveal the multi-optimal mechanisms for dynamic control in drag- onfly wings. By combining the Arnold circulation with such micro/nano structures as the hollow inside constructions of the pterostigma, veins and spikes, dragonfly wings can create variable mass, variable rotating inertia and variable natural frequency. This marvelous ability enables dragonflies to overcome the contradictory requirements of both light-weight-wing and heavy-weight-wing, and displays the multi-optimal mechanisms for the excellent flying ability and dynamic control capac- ity of dragonflies. These results provide new perspectives for understanding the wings＇ functions and new inspirations for bionic manufactures.展开更多
Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered co...Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered corrugation based on the finite element method.It is shown that the vein size in different zones is proportional to the magnitude of the vein internal force when the wing structure is subjected to uniform out-of-plane transverse loading.The membrane contributes little to the flexural stiffness of the planar wing models,while exerting an immense impact upon the stiffness of the 3D wing models with cambered corrugation.If a lumped mass of 10% of the wing is fixed on the leading edge close to the wing tip,the wing fundamental fre-quency decreases by 10.7%～13.2%;if a lumped mass is connected to the wing via multiple springs,the wing fundamental fre-quency decreases by 16.0%～18.0%.Such decrease in fundamental frequency explains the special function of the wing pterostigma in alleviating the wing quivering effect.These particular features of dragonfly wings can be mimicked in the design of new-style reticulately stiffening thin-walled roof systems and flapping wings in novel intelligent aerial vehicles.展开更多
基金Project supported by the National Natural Science Foundation of China (Nos. 11102138 and 11272175)the Fundamental Research Funds for the Central Universities
文摘This paper aims to reveal the multi-optimal mechanisms for dynamic control in drag- onfly wings. By combining the Arnold circulation with such micro/nano structures as the hollow inside constructions of the pterostigma, veins and spikes, dragonfly wings can create variable mass, variable rotating inertia and variable natural frequency. This marvelous ability enables dragonflies to overcome the contradictory requirements of both light-weight-wing and heavy-weight-wing, and displays the multi-optimal mechanisms for the excellent flying ability and dynamic control capac- ity of dragonflies. These results provide new perspectives for understanding the wings＇ functions and new inspirations for bionic manufactures.
基金Project supported by the National Natural Science Foundation of China(No. 50408022)the Visiting Scholarship from the Future Academic Star Project of Zhejiang Universitythe Scientific Research Foundation for the Returned Overseas Chinese Scholars,MOE and Zhejiang Province,China
文摘Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings,we analyzed two planar computational models and three 3D computational models with cambered corrugation based on the finite element method.It is shown that the vein size in different zones is proportional to the magnitude of the vein internal force when the wing structure is subjected to uniform out-of-plane transverse loading.The membrane contributes little to the flexural stiffness of the planar wing models,while exerting an immense impact upon the stiffness of the 3D wing models with cambered corrugation.If a lumped mass of 10% of the wing is fixed on the leading edge close to the wing tip,the wing fundamental fre-quency decreases by 10.7%～13.2%;if a lumped mass is connected to the wing via multiple springs,the wing fundamental fre-quency decreases by 16.0%～18.0%.Such decrease in fundamental frequency explains the special function of the wing pterostigma in alleviating the wing quivering effect.These particular features of dragonfly wings can be mimicked in the design of new-style reticulately stiffening thin-walled roof systems and flapping wings in novel intelligent aerial vehicles.
