Tensile and flexural fatigue properties of glass/aramid and glass/carbon fiber hybrid laminates in polyester and vinylester resins have been evaluated systematically and presented as basic design data in this paper. Seventeen kinds of laminates including basic laminates and combined hybrid laminates were fabricated by hand-lay-up technique and comparatively evaluated. The general hybrid effect was characterized systematically from the viewpoint of hybridization merit of FRP when aramid fiber, carbon fiber, glass/aramid fiber or glass/carbon fiber hybrid reinforcements were substituted for glass fiber reinforcements in the standard glass fiber laminate constitutions for marine use. The test data indicated that the S-N curves of hybrid FRP laminates were not influenced very much by the difference in fracture strain of matrix. It was shown that fatigue strength at 106 cycles decreased approximately 40 to 75 percent of initial static strength. It was also shown that the S-N curves combined laminates could be predicted from the data of basic laminates utilizing a simple rule of mixture.
