TEMPERATURE EFFECT ON IMPACT DAMAGE IN CFRP COMPOSITES LAMINATES

Over the years, there has been major concern over the safety of laminated composites subjected to a low velocity impact. A low velocity impact on laminated composites may encounter various types of damages including delamination, fiber breakage, matrix cracking and fiber matrix interfacial debonding. These types of dam ages cannot be detected visually and lead to structural failure at loads well below design levels. In this Project the CFRP laminates are zero and cross ply were fabricated with LY556 epoxy resin as a matrix and the specimens were cut according to the ASTM D790 using water jet cutting. By using Fractovis Drop weight impact machine, barely visible damage was introduced to the specimen at a constant velocity of 1.5 meter per sec. To identify the effect of temperature, specimens were subjected to impact at ele vated temperature in the environmental chamber. The impacted specimens were further subjected to flexural testing in Tinius Olson 100KU universal testing machine under acoustic emission monitoring to compare the residual strength with the normal specimen. From the flexural results it’s observed that the considerable increment in the impact resistance and residual strength in the specimens impacted at elevated temperatures. From the Acoustic emission monitoring results nature and extent of damage can be clearly observed .