| Popis: |
Bamboo is a typical natural graded material, from the inner layer to the middle layer, and then to the outer layer. The elastic modulus is increasing gradually. The cracks grown on the inner layer and outer layer have different effects on the intensity. In this paper, the influence of the gradient distribution on the fracture behavior of the mixed-mode I and П cracks located in different layers is studied. The displacement measurement of bamboo specimens on asymmetric loading using digital speckle correlation method (DSCM) is performed and the crack tip opening displacement (COD), the stress intensity factor can be obtained. The results show that the COD of the crack in the outer layer is less than that of the crack in the inner layer, the stress intensity factor in the outer layer is greater than that of the crack in the inner layer, that means the property of the gradient distribution of bamboo has the protecting function for the static crack in the inner layer. |
