Numerical Buckling Analysis of Hybrid Honeycomb Cores for Advanced Helmholtz Resonator Liners

Abstract

In order to realize novel acoustic liners, honeycomb core structures specially adapted to these applications are required. For this purpose, various design concepts were developed to create a hybrid cell core by combining flexible wall areas based on thermoplastic elastomer films and rigid honeycomb areas made of fiber-reinforced thermoplastics. Within the scope of the presented study, a numerical approach was introduced to analyze the global compressive failure of the hybrid composite core structure, considering local buckling and composite failure according to Puck and Cuntze. Therefore, different geometrical configurations of fiber-reinforced tapes were compared with respect to their deformation as well as their resulting failure behavior by means of a finite element analysis. The resulting compression strength obtained by a linear buckling analysis agrees largely with calculated strengths of the more elaborate application of the failure criteria according to Puck and Cuntze, which were implemented in the framework of a nonlinear buckling analysis. The findings of this study serve as a starting point for the realization of the manufacturing concept, for the design of experimental tests of hybrid composite honeycomb core structures, and for further numerical investigations considering manufacturing as well as material specific aspects.