Thermo-mechanical Properties of Sandwich Composite Plates with MWCNT Reinforced Honeycomb Core: A Numerical and Experimental Study

In the present work, the bending behavior of honeycomb-cored multi-walled carbon nanotube (MWCNT) reinforced sandwich composite plate was investigated using an in-house finite element model based on higher-order shear deformation theory and commercial Digimat-HC software. Along with various parametric studies, the influence of the weight fraction of MWCNTs, cell size thickness and height of the core on bending behavior, face sheet bending stress and core shear ultimate strength were numerically investigated. Results showed that the central deflection values obtained via the three-point bending test were in good agreement with the developed FEM model and Digimat-HC software. The deviation of experimental values from the developed FEM model varied in the range of 2.73–3.98%, whereas, from the Digimat-HC software, the experimental values deviated in the range of 2.32–4.88%. Irrespective of the test temperature, the CNT-reinforced honeycomb sandwich composite exhibited far superior bending behavior as compared to the neat epoxy composite; displaying 8%, 21% and 12% higher load-bearing capacity at 30 °C, 60 °C and 90 °C, respectively. The MWCNT reinforced honeycomb core sandwich composite displayed the best amalgamation of core shear strength and face sheet bending stress, when the core height, C_h = 5. The developed techniques can be used to determine the dimensions of honeycomb cored sandwich structure, as required for different applications.