Enhanced strength and weakened dynamic sensitivity of honeycombs by parallel design.

Highlights • Parallel design is proposed to enhance the static compression strength of honeycomb. • The static stress can be enhanced by more than 70% for the regular hexagonal honeycomb in the x direction. • The static enhancement coefficient is irrelevant to the average relative density of the honeycomb. • Parallel design not only can improve the dynamic crushing strength of the honeycomb, but also can reduce the sensitivity of the honeycomb to crushing velocity. • Parallel design can easily be generalized to other cellular solids. Abstract This paper proposes a parallel design which can extremely enhance the in-plane property of honeycombs without adding extra mass. Theoretical analysis of regular hexagonal honeycomb with parallel gradient configuration (HPGC) demonstrates that it can achieve a maximum of more than 70% enhancement of static strength in the x direction compared with uniform honeycomb (UH) of the same relative density. Furthermore, static enhancement coefficient is irrelevant to the average relative density of HPGC, which means the degree of enhancement under certain density gradient is constant no matter what the relative density is employed. This is efficient for fast performance-oriented design. The mechanism of strength enhancement is discussed. Result shows that parallel design is applicable to many cellular solids who are eligible for the special relations (for example, the linear relation between graded variable t and relative density and the nonlinear relation between graded variable t and crushing strength). Dynamic analysis shows that the dynamic crushing strength is also enhanced by parallel design. In addition, parallel design is able to reduce the sensitivity of dynamic crushing strength to the impact velocity. Finite element analyses (FEA) are carried out to verify the theoretical results. This novel design provides huge potentials to cellular solids with high-level strength and lightweight applications. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]