Residual Behavior of Sandwich Panels with Flax FRP Faces and Foam Cores after an Impact Event

Abstract

In this paper, the residual properties of sandwich panels with flax fibre-reinforced polymer (FFRP) faces which have been subjected to impact loading will be investigated. The sandwich panels tested in this study were fabricated using a closed cell polyisocyanurate foam with a density of 64 kg/m3 and faces made of a balanced bidirectional flax fabric (nominal areal mass of 400 g/m) and an epoxy resin with an approximate bio-content of 30% after mixing. Each specimen was 1220 mm long, 150 mm wide and approximately 80 mm thick. The sandwich panels will first be subjected to an impact of 100% of the impact energy resisted in previous tests using a drop weight impact test. The span length of the tests will be 1117 mm and a drop weight (10.413 kg) with an impact surface width of 150 mm will impact each specimen at midspan. For these tests, the top face strain, bottom face strain and deflection at midspan will be sampled at a rate of 25 kHz. After the impact, the panels will be tested under quasi-static three-point bending to failure. During this test the load, midspan deflection, and top and bottom face strains at midspan will be sampled at a rate of 10 Hz. The results of the post-impact quasi-static flexural test will be compared with similar flexural tests performed on intact specimens to determine the effect of the impact on the flexural behavior of the sandwich panels. It was determined that the properties of these sandwich panels are not adversely affected by an impact event. There is potential that the impact increases the static capacity of the sandwich panels, however more research is required. This research is part of a larger on-going study and more results will be available at the time of the conference. https://doi.org/10.1061/9780784482247.003