Abstract
Three kinds of representative carbon fiber reinforced unidirectional composite materials are used, and their intralaminar fracture behavior is investigated by using the double-cantilever beam (DCB) specimen with a simultaneous acoustic emission measuring. In Part I, the experimental results on the crack propagation, the bridging fibers, the intralaminar fracture toughness acoustic emission characteristics and microscope observations were obtained. Here, we use a bridging fiber model to analyze the debonding force acting on a bridging fiber and try to estimate the number of bridging fibers during the crack propagating process. At the same time, the intralaminar fracture toughness is calculated by both the adhesive force model and the finite element analysis. As a result, it is found that the intralaminar fracture toughness without the bridging fibers will have a constant value during the crack propagation, but it increases greatly when bridging fibers exist. It is clear that the bridging fibers play an important role in the intralaminar fracture toughness. The debonding forces acting on the bridging fibers and the number of bridging fibers are obtained. Furthermore, the quantitative estimation of the increment of the intralaminar fracture toughness contributed by bridging fibers is made according to the adhesive force model and it is comparable with the results obtained by the finite element analysis.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have