Out-of-plane compression of a novel hybrid corrugated core sandwich panel

Abstract Lightweight sandwich panels with fluid-through cellular cores are promising for applications requiring simultaneous load-bearing and heat dissipation such as the combustion chamber of scramjet. While existing core topologies have exhibited good designability for specific thermal or mechanical requirements, the increasing demand for multifunctional attributes usually points to different core topology designs. Finding a single core topology that possesses excellent mechanical and thermal properties simultaneously remains challenging. To address the issue, the concept of a hybrid core (termed herein as the N core) that combines the conventional corrugated core with the web core was proposed to mitigate confliction between thermal and mechanical designs. Out-of-plane compressive characteristics of the hybrid cored sandwich panel was investigated theoretically, numerically and experimentally. An elastic–plastic analytical model was developed to predict the out-of-plane compressive behavior, with connection strength between facesheets and core as well as non-uniform strut thickness accounted for. For validation, test sample was fabricated using 3D-printing technology and tested under quasi-static out-of-plane compression. The validated model was then employed to exploit optimal configuration of the N core and maximum load capacity of the panel at minimal weight. It was demonstrated that, due to non-uniform strut thickness, the hybrid structure exhibited stepwise deformation, i.e., initial, subsequent and ultimate failures. Under the constraint of equal mass, the load capacity of either the hybrid or corrugated core is superior to the web core, while both the hybrid and web cores outperform the corrugated core in terms of active cooling capacity. For multifunctional applications, the proposed hybrid corrugated core possesses comprehensive thermal and mechanical advantages over conventional corrugated and web topologies.