The hierarchical structure and flexure behavior of woven carbon fiber epoxy composite

The hierarchical structure and flexure behavior of woven carbon fibers epox y composite were investigated in this work. First, the hierarchical structu re of the composite is characterized on three levels: composite, ply, and y am. Structural imperfections,* such as, ply-ply misalignment, ply-ply offse t, and resin pockets, are identified and described. Second, a four-point be nding arrangement is used to study the flexure properties of the composite. Additionally, in-situ traveling microscope and acoustic emission (AE) tech niques are utilized to gain insight to the failure processes during flexure test. AE showed early stages of matrix cracking before visual observation, which makes it a valuable tool for early failure detection.