Stress carrying capacity of miter joint reinforced with fiber reinforced polymer (FRP)

The aim of this study was investigation of the performance of mitered corner joints (L-shaped) reinforced by fibers reinforced polymer (FRP) at maximum stress area under diagonal compression loading. In This way, structural performance of constructed corner joints of two species of beech and fir reinforced by fiber reinforced polymer at polymeric matrix of epoxy with one and two layer of carbon and glass fibers and were investigated. After construction of the mitered joints with wooden dowel and polyvinyl acetate adhesive, the joints were reinforced with FRP composites and then were subjected to diagonal compression loading. Results have indicated that reinforcing layers prevent joint opening, however, failure was occurred at the joint by peeling fibers from wood surface or members fracture near the joints by stress concentration. The results of variance analysis showed that the independent effect of species of joint members and numbers of fibers layer were significant at 95% confidence level. The results showed that use of beech wood in comparison with fir wood, composites reinforced by carbon fibers compared to glass fibers, as well as the use of two layers of fiber compared to 1 layer of fibers, exhibited better performance in constructed joints. The joints made with beech wood and reinforced with 2 layers of composites reinforced by carbon fibers showed the best performance under diagonal compression loading.