Exploring the effects of fiber angle and stacking sequence on the static strength and acoustic emission signature of epoxy-fiberglass composites in marine environments

Abstract

Marine Hydro-Kinetic (MHK) devices encompass promising new technologies designed to harness energy from ocean currents and tides. However, there are unique challenges to successful implementation of MHK devices. Material selection and characterization are crucial steps in the design process as the marine environment can be extremely detrimental to many materials systems. Epoxy-fiberglass composites, the premier material in wind turbine blades are being studied for use in MHK due to desirable price and durability. Preliminary research has shown a significant drop in ultimate strength due to moisture absorption in unidirectional laminates. This research extends these studies by exploring these effects on balanced and unbalanced off-axis fiber angles for a common epoxy-fiberglass material system. Ply by ply analysis is completed to explore the efficacy of a strength reduction prediction method for off-axis laminates. It also extends the study to include acoustic emission analysis to further investigate the material degradation at a micromechanical level. Partial saturation strength reduction in symmetric laminates is also studied.