Bending Behavior of Carbon Fiber Reinforced Plastic Cable with Twisted Structure

In this study, the bending behaviors for a carbon fiber-reinforced plastic (CFRP) cable with a twisted structure were evaluated based on a compression bending test. This test was selected because under three-point and four-point bending, fractures under the indenters make evaluation of the bending properties difficult. Accordingly, the compression bending of a CFRP cable with different lay angles was successfully evaluated. The results showed that the bending strengths obtained by the compression test exceeded those obtained from three- and four-point bending tests by 8% and 1%, respectively, owing to the prevention of the fracture under the indenter. The bending stiffness did not depend on lay angle of the cables, but the compression bending strength increased with an increase of the lay angle. These results were in good agreement with the theoretical relationships between the bending stiffness, bending strength, and lay angle. Thus, the validity of evaluating the bending behaviors of CFRP cables based on compression bending was demonstrated. Moreover, it was found that the bending behaviors of the CFRP cables were related to the lay angle and lay length.