Compressive failure of spruce wood rings reinforced with glass epoxy composite

Abstract

We experimentally tested under radial compressive loads and statistically analyzed rings constructed from spruce wood and reinforced with glass fiber. We used the Weibull distribution in statistical analysis, and tested five types of rings including unreinforced and composite reinforced (CR) as wound around the ring, oriented as two layers at angles of 45A degrees, 60A degrees, 75A degrees and 90A degrees to the column axis. We calculated 95 % reliability of load carrying capacity of the rings by Weibull distribution. The highest load carrying capacity was obtained with CR rings at 60A degrees to the axial axis of the ring. Load carrying capacities of rings at CR90, CR75, CR60 and CR45 were 137, 192, 215 and 126 % greater, respectively, than unreinforced rings. For unreinforced rings, failures resulted from catastrophic breaking of wood materials. None of the reinforced rings failed catastrophically because the outer surface of the rings was reinforced with glass-epoxy composite fiber. Cracks began at the core of the materials under the composite layer for all specimens and resulted in failure of the rings.