Coordinate dependent experimental determination of shear modules for transversly isotropic composites by using wood torsion specimens

In this master thesis, the torsion experiments in which the main experiments tests inorder to declare the mechanical elastic constants were done. The experiments weregenerated into two test groups. Experimental speciments have the circular crosssectional areas in which they are in the from of solid and thick tubular shapes. By thefirst group of experiments and considering that the wood specimens and assumed to betransversely izotropic fiber composite material, the average shear modulus data (G)were obtained from the τ - γ graphics. The experiments were done into two parts thehelp of as, with gauges and without gauges. In the second group of experiments; withthe help of two dataloggers AMR and TDG, the variations of G were tried to bedetermined with respect to r, θ, and z coordinates. In order to do this, through the r, θ,and z coordinate axes, the directions of fibers at 00 and 450 angles to it are used. Theunit deformation information belonging to the shear deformation data were obtainedfrom the gauges which are attached to the definite coordinate points from each gauge,τ - γ graphics is plotted. The variations of shear modulus along the r, θ, and zdirections were defined in terms of parabolic and exponential equations. By this way,shear modulus functions f 1 = G (r ) , f 2 = G (θ ) and f 3 = G ( z ) were seen.Science Code : 914Key Words : Torsion experiment, Shear Modulus, Wood specimen, Fiber compositePage Number : 246Adviser : Asst. Prof. Dr. Ezgi GÜNAY