Kenji Kubomura’s scientific contributions

Two bearing strengths are characterized for four PAN-based and four pitch-based carbon fiber composites of [0°/±45°/90°]3s laminate. It is found that full bearing strength is developed when the edge distance ratio, e/D, is equal to or greater than 3.0 and the side distance ratio, w/D, is equal to or greater than 4.0. Bearing strength in creases with an increase in the fiber strain to failure, and also with the longitudinal com pressive strength of the unidirectional composites. No correlation is evident between the tensile strength of fiber and the bearing strengths. The first peak load in the load versus pin displacement curve is recommended for calculating the bearing strength.

Results are presented on measurements of the bearing strength of four pitch-based and two PAN-based carbon-fiber composite materials of (0 deg/ +,- 45 deg/ 90 deg)3s laminate specimens. The bearing strength was correlated with the mechanical properties of longitudinal reinforcing fibers, and with observations of microstructural damage. It was found that, in both the high tensile and high modulus carbon-fiber composite materials, the full bearing strength develops when the edge to distance ratio equals to or is larger than 3.0, and the side distance ratio is equal to or is larger than 4.0. As the fiber strain to failure becomes higher and also as the longitudinal compressive strength of unidirectional composites becames higher, the bearing strength becomes higher. No corrrelation was found between the tensile strength of the fiber and the bearing strength.