Mechanical properties of combined structures of stacked multilayer Nomex® honeycombs

Abstract To investigate the mechanical properties of combined structures of stacked multilayer Nomex® honeycombs, a finite element model of the combined structures of stacked honeycombs was established to simulate quasi-static compression. The results were compared with test data, thus verifying the accuracy of the simulation. On this basis, a series of simulations were conducted on combined structures of stacked multilayer Nomex® honeycombs with three specifications. The results show that the large-thickness combined structures of honeycombs with similar properties can be obtained by stacking Nomex® honeycombs of the same specification, which solves the problem whereby a single honeycomb tends to fail and a long honeycomb is difficult to produce; however, use of too many clapboards can reduce specific energy absorption (SEA), so an appropriate number of layers must be selected. In the combined structures, stacked Nomex® honeycombs with different specifications yield and deform layer-by-layer from low to high yield strength, producing a controllable, orderly, graded response. Changing the sequence of combination of stacked honeycombs can control the sequence of deformation of different layers in the compression process without changing the overall properties. The ratio of honeycombs with different specifications in the combined structure can determine the strain ratio under plateau stress at each layer, allowing orderly control of ladder energy levels. The research results provide a reference for application of the combined structures of stacked multilayer Nomex® honeycombs.