Microscopic damage due to drop weight impact in plain weave CFRP laminates
Kobayasi Akira; Ogihara Shinji; Kasuya Satoshi; Ishiyama Kazuyoshi
Abstract:CFRP (Carbon Fiber Reinforced Plastics) have been increasingly used aerospace structures because of their weight saving effect. They are used in the form of multidirectional laminates. It is well known that delamination easily occurs in the CFRP laminates under transverse low velocity impact loading, and that the compressive strength of CFRP laminates with delamination reduces substantially. Therefore, the CAI (compressive strength after impact) problem has been studied extensively. However, most previous studies focused on the relationship between the compressive strength and the delamination area. For the design of performance materials, it is important to understand the microscopic damage behavior. There is few study on the microscopic damage progress in plain weave CFRP laminates under transverse loading. In the present study, instrumented drop weight impact tests and static transverse loading tests are conducted on plain weave CFRP laminates, and microscopic damage onset and propagation are observed by an optical microscope and a scanning acrostic microscope. It is found that fiber bundle fracture is dominant in impact loading, and delamination is dominant in static loading. Key Words:delamination, plain weave CFRP, transverse load, microscopic damage, drop weight impact