title: Effect of microstructure on the mechanical and damping behaviour of dragonfly wing veins.
abstract: Insect wing veins are biological composites of chitin and protein arranged in a complex lamellar configuration. Although these hierarchical structures are found in many 'venous wings' of insects, very little is known about their physical and mechanical characteristics. For the first time, we carried out a systematic comparative study to gain a better understanding of the influence of microstructure on the mechanical characteristics and damping behaviour of the veins. Morphological data have been used to develop a series of three-dimensional numerical models with different material properties and geometries. Finite-element analysis has been employed to simulate the mechanical response of the models under different loading conditions. The modelling strategy used in this study enabled us to determine the effects selectively induced by resilin, friction between layers, shape of the cross section, material composition and layered structure on the stiffness and damping characteristics of wing veins. Numerical simulations suggest that although the presence of the resilin-dominated endocuticle layer results in a much higher flexibility of wing veins, the dumbbell-shaped cross section increases their bending rigidity. Our study further shows that the rubber-like cuticle, friction between layers and material gradient-based design contribute to the higher damping capacity of veins. The results of this study can serve as a reference for the design of novel bioinspired composite structures.
authors.affiliation: Institute of Zoology, Functional Morphology and Biomechanics, Christian-Albrechts-University, Kiel, Germany; Department of Mechanical Engineering, The University of Guilan, Rasht, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Rajabi
authors.affiliation: Young Researchers and Elite Club, Lahijan Branch , Islamic Azad University , Lahijan , Iran.
authors.forename: A
authors.initials: A
authors.lastname: Shafiei
authors.affiliation: Department of Mechanical Engineering , The University of Guilan , Rasht , Iran.
authors.forename: A
authors.initials: A
authors.lastname: Darvizeh
authors.affiliation: Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems, Stuttgart, Germany; Department for Biomimetics, Bremen University of Applied Sciences, Bremen, Germany.
authors.forename: J-H
authors.initials: JH
authors.lastname: Dirks
authors.affiliation: Institute of Zoology, Functional Morphology and Biomechanics , Christian-Albrechts-University , Kiel , Germany.
authors.forename: E
authors.initials: E
authors.lastname: Appel
authors.affiliation: Institute of Zoology, Functional Morphology and Biomechanics , Christian-Albrechts-University , Kiel , Germany.
authors.forename: S N
authors.initials: SN
authors.lastname: Gorb
keywords: cuticle; damping; finite-element modelling; insect wing; resilin; rigidity; vein