In-plane dynamic crushing of honeycombs—a finite element study

Dynamic crushing of uniform and density graded cellular structures based on the circle arc model

“…Following the references (Li et al, 2014;Li et al, 2007;Song et al, 2010;Papka and Kyriakides, 1994), the cell wall material of the model is taken to be the bilinear strainhardening material model, which is aluminum (Al) with the following properties: the density, Young's modulus, Poisson's ratio, yield stress and tangent modulus were assigned as 2.7×103 kg/m 3 , 69 GPa, 0.3, 76 MPa and 0.69 GPa, respectively. Also, the behavior of the cell wall material is treated as rate-independent, as was done in the references (Ruan et al, 2003;Tan et al, 2005;Li et al, 2014;Zheng et al, 2005;Li et al, 2007;Song et al, 2010) The model was sandwiched between two rigid plates, as in Figure 1. During the crushing in x direction, the right rigid plate subjected to the constant velocity moved toward left and the left rigid plate kept stationary.…”

“…It was suggested by Ruan et al (2003) that the impact velocity was the major factor that affected the deformation modes of the cellular structure. Based on the numerical simulation consequences, the uniform model gives X-shape, V-shape and I-shape deformation, corresponding to different impact velocities, as shown in Figure 8.…”

Stress Distribution in Graded Cellular Materials Under Dynamic Compression

“…However, the local stress cannot be calculated in a similar manner and the mission of calculating the local stress field for cellular materials seems to be impossible. Fortunately, it was observed that the propagation of shock wave is in a nearly one-dimensional form when cellular materials are crushed under high-velocity impact (Reid and Peng, 1997;Ruan et al, 2003;Tan et al, 2005a;Zou et al, 2009;Liao et al, 2013) and the one-dimensional approximation is popularly used. Thus, we can focus on the one-dimensional stress distribution and use the force on the cross section of cellular material to calculate the cross-sectional stress.…”

“…Several shock models and mass-spring models have been proposed to understand the shock wave propagation in cellular materials under dynamic impact, such as the R-PP-L (rate-independent, rigid-perfectly plastic-locking) model (Reid and Peng, 1997), the mass-spring model (Li and Meng, 2002), the E-PP-R (elastic-perfectly plastic-rigid) model (Lopatnikov et al, 2003), the power law densification model and the D-R-PH (dynamic, rigidplastic hardening) shock model . Because the assurance of the repeatability of samples and the measurement of local stress and strain states have not been well solved by experimental techniques, finite element (FE) method has been applied to simulate the dynamic crushing of cellular materials, such as regular/irregular honeycombs (Ruan et al, 2003;Zheng et al, 2005;Liu et al, 2009;Zou et al, 2009;Hu and Yu, 2013) and open-/closed-cell foams Zheng et al, 2014;Sun et al, 2016). The typical features of stress enhancement and deformation localization can be appropriately represented.…”

Compact energy absorbing cellular structure

“…However, due to low dynamic effects and strain rates, it is reasonable to assume that their contribution to the magnitude of collapse load and energy is small and hence neglected [10].…”