Honeycomb failure processes under in-plane loading

Cellular solids such as honeycombs and foams are widely used as structural materials for their low density and high specific stiffness. Under compression or shear loading buckling may occur in cells, and complex deformation modes can result in sudden variations in the strength characteristics of the cellular material. In this paper, the behaviour of regular hexagonal honeycombs under general in-plane loading (compression, traction and shear) is examined by experimental tests and numerical evaluation. In addition, the influence of geometrical imperfections on the failure process is considered. A set of uniform deformation fields is imposed on several honeycomb models with different imperfections in order to determine the overall strength properties, the principal buckling modes and the post-buckling behaviour. Experimental tests are properly designed in order to obtain a complete nonlinear in-plane mechanical characterisation of an Al 3033 honeycomb. Moreover, all the numerical analyses are performed by means of an in-house developed FE code. (c) 2012 Elsevier Ltd. All rights reserved.