Fiber-Reinforced Composite and Wood Bonded Interfaces: Part 2. Fracture

The evaluation of durability and shear strength of FRP-wood bonded interfaces is presented in Part 1 of this two-part study (see Davalos et al. [1]); here, in Part 2, an innovative contoured double-cantilever beam (CDCB) specimen is used to evaluate Mode I fracture of bonded interfaces, and interface fracture toughness data are experimentally obtained for dry and wet conditions. The specimens are designed by the Rayleigh-Ritz method to achieve a linear rate of compliance with respect to crack length. The proposed CDCB specimen is an efficient tool to evaluate Mode I fracture of hybrid interfaces, and the fracture toughness data obtained can be used to predict whether or not a bonded interface will delaminate under general service conditions. Based on the results of this two-part study, recommendations and guidelines are given for evaluation and qualification of FRP-wood bonded interfaces; the methods presented are useful for designing bonded joints, evaluating in-service durability of interfaces, and obtaining fracture toughness data for FRP-wood material combinations.