2014 年 63 巻 5 号 p. 362-367
A novel experimental method was proposed for characterizing the compressive properties of composite materials under impact loading. Split Hopkinson pressure bar system was employed to carry out the dynamic compression tests. The dynamic stress-strain relations could be precisely estimated by the proposed method, where the ramped input, generated by the plastic deformation of a zinc buffer, was effective to reduce the oscillation of the stress field in the specimen. The longitudinal strain of gage area could be estimated from the nominal deformation of gage area, and consequently the failure process could be grasped in detail from the stress-strain relation. Finite element analysis was also carried out to confirm the validity of the proposed method. Numerical results demonstrated that the nonuniformity of the stress field could be negligible by using the ramped input. The dynamic compressive strength of a twilled-woven carbon-fiber/epoxy composite was slightly higher than the static compressive strength.