Experimental Investigation of Mode-I Fracture Properties of Parallel Strand Bamboo Composite

Parallel stand bamboo (PSB) is a high-quality wood-like bamboo composite. Failure due to cracking is a major concern in the design of PSB components for building structures. The mode-I fracture properties of PSB composite were studied. The wedge splitting method was employed as the test approach. Numerical analyses were conducted to determine the appropriate test specimen dimensions so that valid fracture toughness could be obtained. An R-curve was evaluated in accordance with the equivalent linear elastic fracture mechanics (LEFM) theory. It was found that the initial crack depth ratio should be less than 0.4 for the fracture toughness test. The fracture toughness of PSB is higher than that of commonly used woods, and their fracture behavior is similar, exhibiting quasi-brittle behavior. The R-curve of the PSB exhibits rising behavior until the critical crack length is reached. However, the post-peak R-curve exhibits a descending behavior, contrary to that of quasi-brittle materials, which present a plateau in post-peak crack extension.