LOAD-CARRYING BEHAVIOR OF FIBER REINFORCED WOOD PROFILES

摘要

The objective of this research is to provide engineered wood products on the basis of formed wood profiles for structural applications. The formed profiles can be optionally reinforced with technical fibers and/or textiles laminated to the outer wood surface. The purpose of such composite confinement is to strengthen the relatively thin-walled sections and to protect the wood against environmentally induced damage. This paper discusses the load-carrying behavior of light-weight columns with circular hollow cross section. Full-scale axial compression tests were conducted to evaluate the structural performance of the tubes. Following parameters were investigated: (a) type of fiber reinforcement, (b) fiber orientation, (c) thickness of the reinforcement, (d) loading conditions - centric or eccentric, (e) slenderness of the tubes and (f) influence of connections. The static tests have shown that wooden tubes are capable of sustaining high buckling loads as far as brittle failure modes can be prevented. Such failure type was observed for unreinforced columns. The longitudinal splitting of the profiles was due to the expansion of the tubes in circumferential direction resulting in a tension perpendicular to grain failure. The tests on reinforced tubes demonstrated that load-carrying capacity and ductility of timber profiles can be significantly enhanced by composite confinement. The failure mode that caused the damage of the reinforced columns was compression failure in wood. The experimental results reveal that the relatively thin-walled sections (fiber reinforced) are not prone to local buckling failure due to geometrical discontinuities or imperfections. The innovative developments may set the basis for the future of high capacity timber structures, especially in case of highly loaded members with large cross sections.