Mechanical properties of Miura-based folded cores under quasi-static loads

• The mechanical properties of a variety of Miura-based folded core models are studied.
• Curved fold lines improve the compressive and shear performances of folded cores.
• Multiple layered folded cores exhibit better resistances to bending.
• Folded cores have comparable shear and bending performances to a honeycomb core.

Sandwich structures with folded cores are regarded as a promising alternative to conventional honeycomb sandwich structures in the aerospace industry. This paper presents a parametric study on the mechanical properties of a variety of Miura-based folded core models virtually tested in quasi-static compression, shear and bending using the finite element method. It is found that the folded core models with curved fold lines exhibit the best mechanical performances in compression and shear while the multiple layered models outperform the other folded core models in bending. Furthermore, the folded core models are compared to a honeycomb core model with the same density and height. In this case, it is shown that the honeycomb core has the best performance in compression while the folded cores have comparable or even better performances in the shear and bending cases. The virtual test results reported in this paper can provide researchers with a general guideline to design the most suitable folded core structure for certain applications.