Out-of-plane shear property analysis of Nomex honeycomb sandwich structure

Abstract

Honeycomb sandwich structure finds immense applications in aerospace manufacturing and other similar fields. The Nomex honeycomb sandwich structural material exhibits a complex structure and boundary conditions, making it difficult to obtain exact solutions for the equivalent out-of-plane shear modulus and shear strength of the Nomex honeycomb using current analytical methods. To this end, based on the energy method, the Kelsey model is simplified in this paper. Then, distribution of the shear forces in the longitudinal and transverse directions of the Nomex honeycomb core is analysed using the simplified model. Considering the effect of the wall thickness of the honeycomb core on the ultimate strength, the analytical expressions of the out-of-plane shear modulus and shear strength of the Nomex honeycomb are proposed. The shear properties and failure process of the Nomex honeycomb in two directions are then analysed experimentally. The accuracy of the analytical expressions of the equivalent shear modulus and shear strength is verified experimentally. The equivalent out-of-plane shear modulus and shear strength of the honeycomb was demonstrated to be effectively predicted by the analytical approach.