Dai-Heng Chen

Prediction of failure modes and peak loads in lattice sandwich panels under three-point loading

In this study, the failure behaviour of lattice sandwich panels under three-point loading has been studied using a nonlinear finite element analysis. The failure mechanisms of lattice-cored sandwich panels can be classified in three modes; facesheet yielding, facesheet wrinkling and core shear. When the panel fails due to facesheet yielding or core shear, the evaluation of the strength of the lattice-cored panel can be undertaken in the same manner as that of a foam-cored panel. In contrast, when wrinkle-like deformation occurs in the facesheets, the failure load can be estimated from the buckling stress of the facesheet. The failure mode map for the lattice-cored panel with the coordinate system tf /l and ρ c * / ρ s can be described by the analytical equations that predict the three failure modes. The failure mode map highlights the dominant failure modes for the lattice-cored sandwich panel based on the key design parameters tf /l and ρ c * / ρ s .

Estimation of Mechanical Properties of Micro-Lattice Panel with Irregular Cells

In our study, the uniaxial tensile response of lattice panel with missing cell region was investigated using nonlinear FE analysis. In particular, the effects of missing cell size and shape on the initial stiffness E∗ and the plastic collapse strength σpl∗ were discussed. The initial stiffness is mainly affected by the ratio of missing cell height h∕h0 as well as the missing cell width w∕w0, and independent of the unit-cell shape. On the other hand, the plastic collapse strength is mainly dominated by the missing cell width w∕w0 only, which implies that the strength is affected strongly by the tensile strength at the front of the missing cell region.

Study on Bending Collapse of Thin Plate with Corrugated Cross-Section

In this paper, the collapse behaviors of thin plate with corrugated cross-section subjected to three-point bending are studied by using the fin ite element method. In order to estimate the energy-absorption characteristics of the beam, it is vital to understand the relation of load and displacement. It is found that the load de creases by flattening of the cross-section of the beam, and the flattening shape can be quantitatively expressed by using curvature radius of the plane of the top and bottom in the cross-sec tion. Based on an idea that the external work is mainly expended by the flattening deformation of the cross-section, a new prediction method is proposed for estimating the relation of l oad and displacement. Its validity is verified by comparing with the numerical results by FEM under various conditions.