Abstract
The purpose of this study is to clarify effects of fabrication condition on fiber orientation state and mechanical properties of braided CFRP pipes. Two types of braided CFRP pipes, cylinder pipes and rectangular pipes were fabricated. And the braided CFRP pipes with longitudinal fibers and those without longitudinal fibers were also fabricated by changing braiding angle. Four-point bending test was performed for each specimen. The bending modulus of both of cylinder pipes and rectangular pipes was increased with a decrease in the braiding angle. The bending strength of cylinder pipes was increased with a decrease in the braiding angle, but that of rectangular pipes with longitudinal fibers was decreased with a decrease in the braiding angle. By measuring the strains and observe the cross section of the specimens, the following factors to decrease the bending strength were clarified, The factors were stress concentration caused by localized deformation and Performance decline of fiber strength caused by the crimps of the middle-end-fiber.
