Influence of core spacing on bending properties of AlSi10Mg lattice sandwich panel formed by selective laser melting

Abstract

The light-weight and high-stiffness metal lattice sandwich structure formed by selective laser melting has an important application prospect in aerospace, military and other fields. In this study, the response of square lattice sandwich panels with different core spacings under three-point bending was analyzed by finite element analysis, and the results were verified by experimental samples formed by selective laser melting. The results show that there is a linear relationship between the core spacing and cylindrical bending stiffness when the core spacing is within a certain range, the influence of core spacing on cylindrical bending stiffness is very significant and the influence of core spacing on the cylindrical bending stiffness of the square lattice sandwich panel of 45° is greater than that of the square lattice sandwich panel of 0°. The cylindrical bending stiffness of square lattice sandwich panel of 0° and 45° is basically the same under the same relative density when the relative density is within a certain range, which means that they have similar cylindrical bending stiffness under the same weight. When the relative density is less than 5%, the relative density has a significant influence on the cylindrical bending stiffness, and the influence decreases when the relative density exceeds 5%. With the increase of the core spacing, the stress concentration area is transferred from the part of panel under the loading pad to the ends of cores between the support pads due to the reduction of the cylindrical bending resistance of the lattice structure. According to the mechanical analysis, the initial load prediction formula for the yield and plastic stages can be proposed, The comparison between the theoretical results and the FEA results shows that the relative error is less than 13.6%, indicating that the formula is relatively accurate. The experimental results are in good agreement with the FEA results, especially for the cylindrical bending stiffness, the relative error between the FEA value and the experimental value is only less than 6.5%, indicating that the three-point bending deformation and mechanical properties of the lattice sandwich panel can be effectively predicted by FEA.

Keywords

• lattice sandwich panel
• selective laser melting
• finite element analysis
• bending properties