The Compressive and Shear Characteristics of Miura-ori Forms as Core Materials of Sandwich Structures
D. Karagiozova, Meng Shu Wang, Guoxing Lu
Abstract
Abstract The mechanical properties of Miura-ori foldcore metamaterials were studied using finite element simulations. The responses of foldcores with various topological parameters to quasi-static out-of-plane compression and shear loading were analyzed using the relative density as a governing parameter. The non-unique relationships between the core density and the materials’ strength in the examined loading directions were revealed, pointing out the strong influence of the Miura-ori topology. Linear relationships were established between the elastic moduli and relative densities of the Miura-ori metamaterials while power-law functions of the relative density with different exponent constants were established for the strength in different loading directions. It was shown that the Miura-ori materials possess the highest strength under shear in the $${X}_{1}-{X}_{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>1</mml:mn> </mml:msub> <mml:mo>-</mml:mo> <mml:msub> <mml:mi>X</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:mrow> </mml:math> plane and it increases with the increase in the relative density. However, this characteristic is strongly influenced by the sector angle $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> . In general, the difference between the two shear strengths increases when increasing the relative density by using thicker cell walls. It is noted that the strength of the Miura-ori materials as a function of the relative density is nearly constant with respect to the cell dimensions if the values of folding angle $${\gamma }_{0}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>γ</mml:mi> <mml:mn>0</mml:mn> </mml:msub> </mml:math> and sector angle $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> are given. The mechanical characteristics of the Miura-ori material with equal relative density, which exhibits the highest strength among the analyzed origami models, are compared with the out-of-plane compression and shear responses of prismatic hexagonal honeycomb. It is observed that compression and shear responses of the honeycomb outperform the Miura-ori foldcore in all loading directions when considering large deformations.