Experimental and numerical analysis of novel multi-layer sandwich panels under three point bending load

Abstract In this study, mechanical behavior of multilayer corrugated core laminated composite sandwich panel subjected to quasi-static three-point bending is investigated experimentally as well as numerically. Parameters such as contact force, energy absorption and specific absorbed energy (unit mass energy) for different geometries of corrugated core (rectangular, trapezoidal and triangular) are studied during loading process and failure. Composite plates and corrugated cores have been manually made using ML506 epoxy resin with 15% hardener and 45% volumetric woven glass fibers. Experimental results show that multilayer sandwich composite panels not only strengthen the structure in the quasi-static three-point bending process, but also make the absorbed energy to grow significantly by increasing the contact force and displacement up to the complete failure. The main mechanisms of damage and failure of sandwich panel specimens during load bearing process are matrix cracking, fiber breakage, delamination, local indentation, global bending, crushing and buckling of cell walls and face sheet and core de-bonding. Rectangular geometry of corrugated core, in terms of energy absorption and specific energy exhibits better results in comparison to other shapes. Numerical simulation using ABAQUS FEA package led to results, which are in good agreement with experimental ones and make it possible to use simulation instead of costly tests for analysis and design.