Tiled Composite Laminates

Abstract

This article describes our efforts to develop a meso-scale in-plane tiling technique for fiber-reinforced composite laminates. Such a technique expands the design space of the laminate, and the ability to tailor local laminate properties may provide a means, for example, to mitigate stress concentrations that arise in places such as along free edges of the laminate. Preliminary fabrication of tiled laminates produced material with an elastic modulus that is nearly equal to that of continuously reinforced laminates; however, the strength of these first specimens was significantly reduced. Finite element analyses were then performed to characterize the effects of features unique to tiled composite laminates, such as the existence of resin-rich tile-to-tile interfaces, and to explore the effects of relative arrangement of tiles through the thickness of the laminate. This led to a novel composite joint geometry as well as recommendations to minimize strength reduction. Strength retention of laminates fabricated using the new design guidelines was experimentally found to exceed 92% in comparison with the traditional analogs. Finally, we discuss the potential application of composite tiling for the suppression of free-edge delamination.