DETERMINING OPTIMUM CFRP LAMINATE THICKNESS FOR A MOBILE FOREST BRIDGE GIRDER

Abstract

The objective of this study was to determine the optimum thickness of carbon fibre reinforced polymer (CFRP) laminate needed to reinforce a 10 m span of girder in a modular and mobile forest bridge. Finite element analysis was carried out using the Autodesk Mechanical Simulation program. The simulation was carried out by varying CFRP laminate thickness and recording the resulting stress, strain, deflection and safety factor values. The CFRP of 6 mm thickness was selected to reinforce the 10 m timber beam due to stronger and stiffer behaviour of the material under applied loading. Intersection point of stress values trend between the top and the bottom side of timber beam indicated that 6 mm was the optimum thickness for the specimen. Reinforced 2 m timber beams recorded decreased stress on the top and displacement at the bottom side of specimens by up to 33.43 and 61.56% respectively. Knowing the optimum thickness of CFRP laminate for its intended purpose would allow the structure to be designed and fabricated at its lightest weight without compromising the capability of the structure during applied loading. The proposed modular and mobile forest bridge is expected to solve accessibility problems for post-harvesting research activities.