Low Velocity Impact Response of Bio-inspired Fiberglass Woven Composites

摘要

For many years, nature has provided some of the most effective solutions tornchallenging problems that men have faced. Scientists and researchers have tried tornmimic natures approach in order to improve and advance human`s life. In this study,rnthe multistate structure of turtle shell is used to improve the impact resistance of out ofrnautoclaved polymeric composite laminate. The optimally designed turtle shellrnpossesses three layers: The exterior and interior which made out of cortical bone andrnthe middle layer which consists of cancerous bone. This interesting structure providesrnhigh stiffness on the outside, especially under out if plane loadings while giving arnpossibility of small elastic deformations on the inner side. The shell comprises of arnmultiphase sandwich composite structure of functionally graded material havingrnexterior bone layers and a foam-like bony network of closed-cells between the twornexterior bone layers. This concept is used in designing an out of autoclaved wovenrncomposite in order to minimize the deformation and damage in the composite whenrnsubjected to low velocity impact loading. The progressive deformation and damagernbehavior of composite panels with polymer membrane impacted by drop-weights atrnfour different velocities were investigated. The specimens tested were made of wovenrnfiberglass fabric/ toughened epoxy (cured at 1200 C). During these low-velocityrnimpact tests, the time-histories of impact-induced dynamic strains and impact forcesrnwere recorded. The damaged specimens were inspected visually. Test results revealedrnthat the polymer membrane layer plays a significant role on the overall deformationrnand damage behavior of the composites under impact loading. These findings couldrnprovide fundamental understanding of structure-property phenomena and biologicalrnpathways to design efficient energy absorbing bio-inspired composite materials forrnvarious composite structures which are susceptible to the impact damage.