Through-Thickness Compressive Characteristics of Laminated Composites at High Rates of Strain
Takashi YOKOYAMA
Abstract:Through-thickness compressive characteristics of laminated composites at high rates of strain are evaluated using the standard split Hopkinson pressure bar. Three types of laminated composites, namely symmetric cross-ply carbon/epoxy, plain-woven carbon/epoxy and plain-woven E-glass/epoxy with almost the same thickness are tested at room temperature. Cylindrical compression specimens are machined such that the longitudinal direction of each specimen is parallel to the thickness direction of the laminates. The effects of strain rate, type of reinforcing fiber and prepreg form on the secant modulus, ultimate compressive strength, ultimate compressive strain and absorbed energy are examined in detail. It is shown that the cross-ply carbon/epoxy laminated composite exhibits the highest strength characteristics at low andhigh rates of strain, and there is no correlation between the absorbed energies and the Charpy impact energies for the laminated composites tested. Key Words:Absorbed energy, CFRP, Charpy test, GFRP, Hokinson bar, Impact loading, Laminated composites, Secant modulus, Strain rate, Ultimate compressive strength, Ultimate compressive strain