Abstract
Impact three point bending tests on CFRP and GFRP were carried out by using a split-Hopkinson pressure bar technique. Ramped incident waves were produced by plastic deformation of zinc and were applied to the specimens. Smooth transmitted stress waves without high frequency fluctuations were obtained and it was possible to evaluate the stress-strain relation precisely. Bending moduli for CFRP and GFRP were found to be almost independent of the strain rate investigated. The maximum bending stresses of the both materials were slightly rised with an increase of strain rate in the relatively low strain rate range, while their strain rate dependence was markedly increased in the high strain rate range. Non-linear deformation behaviour was initiated by shearing fracture in a local compression region of specimen adjacent to the central loading point, followed by the delamination, and was finally terminated by tensile fracturing in the tension region.
