No abstract

This study experimentally investigates the mechanical properties and behaviors of the hollow circular composite shafts, which are widely used in the industry and operated under a variety of environmental influences. Within the context of this study, glass, carbon and kevlar fibers were utilized as fiber materials and epoxy resins were preferred as the matrix material for hollow circular composite shafts. Composite shafts having 80 mm, 200 mm, 250 mm length and different internal diameters were used for three-point bending tests. Composite hollow shafts were manufactured by utilizing filament winding method at different orientation angles (θ = 45°, 60°, 75°, 80°, 88°). The bending behaviors of the hollow circular composite shafts manufactured were repeated separately for each sample in three-point bending tests. The results obtained were evaluated inter se, displayed in graphics and necessary considerations were addressed.

For this study, woven glass and carbon fibres reinforced composite materials were produced. Composite materials have been produced with eight laminates. For experimental study, specimens with 10 mm internal hole were prepared. Then, these specimens were repaired by using adhesive and composite patches with different repair parameters. Two different bonding patch type were used for external bonding patch repair of the specimens. These were wet lay out patches and prepreg patches. Test specimens were prepared in necessary curing temperatures and laboratory conditions. By performing the unidirectional tensile test to these specimens, the ultimate failure loads of these repaired specimens were indicated. By comparing these ultimate failure loads of repaired specimens that prepared with various parameters, the effects of several repair parameters on the ultimate failure strength are investigated. These repair parameters are patch bonding area (D/W ratio), bonding length, adhesive thickness and patch thickness.