Experimental and numerical study on the mechanical response of Nomex honeycomb core under transverse loading

This paper presents an experimental and numerical investigation on the mechanical response of the Nomex honeycomb core subjected to transverse loading. Here, a series of tensile, stabilized compressive and step-by-step compressive tests were carried out, also a meso-scale finite element modelling method was developed to simulate the resin-paper-resin layered honeycomb cell walls by employing explicit shell elements. Through the analysis of the test results, the brittle fracture behaviour of the phenolic resin coating is recognised as a main reason of the honeycomb collapse. Both the strength and modulus of the honeycomb core in tension are higher than those in compression, due to the local buckling of the thin cell walls at a quite low level of compressive loading. From the numerical analysis, it was found that the volume of the resin coating has a positive effect on the collapse strength of the honeycomb core, however has no influence on the collapse strain. Moreover, the modulus of the resin coating has a positive effect on the collapse strength but a negative effect on the collapse strain. In addition, the strength of the resin coating has positive effects on both the collapse strength and strain of the honeycomb core.