S.M.R Khalili - Professor Center of Excellence for Research in Advanced Materials and Structures, Faculty of Mechanical Engineering, K.N. ToosiUniversity of Technology, Tehran, Iran
S Moharrami - M.Sc. StudentCenter of Excellence for Research in Advanced Materials and Structures,Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, Iran

Nowadays, sandwich composite panels are widely used in various industries like aerospace, construction, ship building, armors due to their specific strength and stiffness. Due to their significant bending strength, more over theability to resist the compression loads without sudden breaking, they are used in various mechanical load bearing structures, especially in aircraft engineering. In this experimental work, Polyurethane foam has been changed toauxetic foam with negative Poisson's ratio by making changes in its cell structure using compression and various heat treatments. The auxetic foam is used as core material in sandwich panels with a facesheet made of glass fiber reinforcedcomposite. The sandwich panel specimens are prepared for flatwise compression test according to standard. Experimental results revealed that the compression modulus of the sandwich panels with auxetic foam core increasedby 205%, and the compression strength is improved by about 672% as compared to sandwich panels with core material made of conventional foam.

Sandwich Panel, auxetic Foam, Polyurethane Foam, Negative Poisson's Ratio, Flatwise Compression Test