Experimental Evaluation of the Effect of the Structure of Composite Rings on Their Properties in the Radial Direction

Based on the results of bending tests on cut glass-fiber-reinforced plastic rings with a longitudinal-circumferential reinforcement, their radial peel strength is evaluated. The effect of the fiber layout on the properties of the rings in the radial direction is investigated. It is shown that their radial tensile strength only slightly depends on the fiber layout but is basically determined by the properties of the polymer interlayer between the fibers. In radial tension, the presence of fibers in the polymer layer leads to a strain concentration, which results in a premature failure of the polymer phase of the composite. The strain-concentration factor cannot be used for an accurate prediction of the breaking stresses or strains of the composite, because of different failure modes of the pure resin and the composite.