The influence of the structural features of dragonfly wings, including the sandwich-type configuration of longitudinal veins and the longitudinal corrugations, on the impact response of a bio-inspired structure is investigated. According to experimental observations of the wing morphology, a novel foam-based composite structure is introduced consisting of E-glass/epoxy face-sheets bonded to a polyurethane foam core. A finite element model is employed to simulate the structural responses of the biomimetic structure under low velocity impact. The initiation and evolution of the impact-induced damage in composite skins are simulated by applying a user-defined progressive damage model together with the interfacial cohesive law for intra- and inter-laminar damages, respectively. To simulate the nonlinear behavior of the foam core, a crushable plasticity model is implemented. The numerically obtained results are found to correlate with the experimentally measured ones, acquired by drop-weight testing on a bio-inspired structure. It is numerically predicted that reinforcing the structure with the veins gives the more impact load-bearing capacity and the longitudinal corrugation can increase the stiffness and damage resistance of the structure. Effects of the change in impact location, the configuration of the veins and the corrugated angle on damage resistance of the structures are fully discussed.

This work is carried out by Azadeh Arjangpay, Abolfazl Darvizeh, Mehdi Yarmohammad Tooski

1. Department of Mechanical Engineering, University of Guilan, Rasht, Iran

2. Department of Mechanical Engineering, Islamic Azad University, Bandar Anzali Branch, Bandar Anzali, Iran

3. Department of Mechanical Engineering, Islamic Azad University, South Tehran Branch, Tehran, Iran

and published on the JBE Volume 15, Issue 5, September 2018, Pages 859–871.

Full text is available at https://link.springer.com/article/10.1007/s42235-018-0073-1