A Study On Mechanical Properties Of X-cor Sandwich

Recent years, advanced composite materials were widely used in aviation, spaceflight, ship and public traffic, as structural and functional materials, promoting these fields notably.The appearance of sandwich structures adapts to the needs of high strength, high stiffness and weight-efficiency in the structures of aircraft and bullet train. For ameliorating the disadvantages of honeycomb composites, a novel Z-pinned foam core sandwich named X-cor was presented by Carstensen etc.As a rising sandwich material, the basic mechanical properties of X-cor should be further studied. Based on literature and the condition of our technics equipment, we fabricated X-cor materials by ourself, including foam core sandwich of 15~0 Z-pinned angle with 12.7mm thickness core, 25~0 Z-pinned angle with 8mm thickness core, each group of them had one same casting part unreinforced to contrast. This paper studied the basic mechanical properties of X-cor sandwich by experiments, including out-of-plane shear, compression and three point flexural experiments. By contrasting with unreinforced specimens, found X-cor can improve the basic mechanical properties notablely, especially compensate the shortcomings of low stiffness and strength of sandwich inducing by the weak foam core. So this sandwich materials can be used on the primary load bearing structure in aircraft, submarine and bullet train, which possesses well application foreground.We studied the basic mechanical response and breakage mechanism of X-cor sandwich by experiments, and contrasted with unreinforced specimens. We found the existence of Z-pin optimize the mechanical properties, change the failure map, make this materials have different deformation from the initiation of cracks to crashing failure.The paper established the method for predicting shear modulus of X-cor, the prediction results accord with experimental data well. Various factors which affect the property of shear modulus are demonstrated, the shear modulus increases with the modulus, diameter, and volume fraction of pins, and reaches it's maximum at the angel of 45° on definite volume fraction. The best thing for X-Z-pin reinforced foam core sandwich is that it's programmable by altering the various design parameters to optimize the mechanical properties.The paper studied and discussed the model for predicting strength of X-cor based on experiments and literatures. By employing restriction correction coefficient, ameliorate the compression strength model based on Euler buckling load for a simply supported column on a foundation presented by Cartie', make the prediction results approach and agree better with the measured results. At the same time, based on different assumptions, we discussed the shear strength prediction model of X-cor, the...