LOW-VELOCITY IMPACT RESPONSE OF RESIN INFUSION MOLDED FOAM FILLED HONEYCOMB SANDWICH COMPOSITES

In this study the low-velocity impact and post-impact response of low- cost resin infusion molded sandwich composites utilizing a foam filled honeycomb core with graphite and S2-glass fabric facesheets (skins) h as been investigated. The foam filled honeycomb core provides combined advantages of the traditional foam core and honeycomb sandwich compos ites in that it possesses high shear and bending stiffness, and cell w all stability. The low velocity impact response of 101.6 mm x 101.6 mm sandwich plates is studied at five energy levels representative of da mage initiation and propagation. The low velocity damage is correlated to ultrasonic C-scan images, vibration resonance frequency and optica l microscopy observations. The results indicate that the damage tolera nce is enhanced by the foam filled honeycomb core and that load requir ed to initiate damage is independent of the facesheet type for any spe cific core/facesheet thickness. The sandwich composites with S2-glass facesheets are found to possess more damage tolerance as compared to t he graphite facesheets.