Mechanical behavior of gradient aluminum honeycomb sandwich panels

Gradient aluminum honeycomb structure is an effective energy-absorbing structure. According to the concept of gradient rate, four types of aluminum honeycomb sandwich components with the same mass and different gradient rates were designed by changing the cell wall length of the honeycomb core layer. On the basis of the same mass, the deformation mode of gradient aluminum honeycomb sandwich structure under quasi-static state, as well as the dynamic response and energy absorption characteristics of layered homogeneous honeycomb structure under impact load and layered gradient honeycomb structure with different gradient rates were compared by combining quasi-static compression experiments and the deformation and mechanical properties of gradient aluminum honeycomb sandwich structures under quasi-static and impact states, which were simulated by nonlinear finite element. The results show that during the quasi-static compression process, the deformation of the aluminum honeycomb gradient sandwich panel has obvious localization characteristics. The deformation of the honeycomb core is preferentially low density until compaction, and the densification strain difference between the layers is gradually decreased as the core layer density is increased. Besides, under high-speed impact, the gradient honeycomb panel is not strictly deformed step by step in the quasi-static process until it is densified. It is the linear elastic deformation, elastic buckling, plastic collapse and compaction that occur as a whole under the interaction of the hammer head inertia and the core layer density. In addition, during the range of the gradient rate designed in this paper, when the gradient rate is γ1=0.0276, the energy absorption of the gradient honeycomb sandwich panel is the best. Compared with a homogeneous honeycomb sandwich panel of the same mass, the energy absorption is improved by 10.63%