Abstract:

The opining and shear interlaminar fracture behaviors of meso bamboo have been studied in this paper. Based on the energy concept，double cantilever beam（BCD）sample and end notched flexure （ENF）sample were applied to measure the model Ⅰ and model Ⅱ interlaminar fracture toughness of meso bamboo. The results show that： model Ⅰ and model Ⅱ fracture toughness of bamboo parallel to grain are basic properties of bamboo，which is the resistance of the opining and shearing cracks extend. The spread area of the crack of model Ⅰ shows the characteristic of smooth fiber and flat matrix. These manifest that the strength of the basictissue and interface strength of fiber/basic tissue is relatively weak. The spread area of the crack of model Ⅱ shows the characteristic of hackle shear deformation. These manifest that the basictissue brings the relatively big shear deformation before rupture. So the latter absorbs more fracture energies than the former. Judged by the whole morphologies of rupture surface，the cracking was carried on among basictissue and through the interface of fiber/tissue.Both of them are selfscaling fracture and with no fiberbridging.

Key words: bamboo, interlaminar fracture toughness, model Ⅰ, model Ⅱ