Compression behavior of polyurethane foam sandwich with composite stiffeners: experimental and numerical studies

Abstract

The compression behavior of Polyurethane (PU) foam carbon composite sandwich is studied with introducing stiffened keyway. The foam core is slotted and carbon composite layers are built with stiffened keys in single as well as two directional. Sandwich samples are prepared by co-bonded keys and tested experimentally under uniaxial compression. The load capability of bidirectional stiffened keys exhibited drastic improvement. For the same amount of height reduction during compression, the maximum load capability upto 406% is seen in bidirectional stiffened key sample as compared to the other samples. Further the improvement in load carrying capacity is seen at the tail off regime indicating the importance of key stiffening concept. Microscopic analysis is done to verify the sample of foam and the interface with keyway. Three dimensional finite element model is made and stiffened key configurations are analysed. Ogden material model with varying parameters are studied. A good correlation with finite element analysis and experimental test values are obtained.