Experimental and Optimization Study of Compression Behavior of Sandwich Panels with New Symmetric Lattice Cores

The paper presents a novel core design for sandwich panels and conducts an experiment to determine whether the mechanical strength of symmetric aluminum lattice core sandwich panels can be improved. Both Design of Experiments (DOE) and Response Surface Methodology (Box-Behnken) were used to establish a quantitative relationship between the strength-to-weight ratio and the input parameters. The thickness of the sheet, the height of sandwich panels, and the width of the seat were all considered design variables to achieve the optimal state. The maximum Initial Peak Crushing Forces (IPCF) were then determined using quasi-static axial flatwise compression tests. This study found that the model's predicted values were consistent with the experimental results. As a result, the parameters were optimized using the Design-Expert software to maximize the initial peak force while minimizing the weight. The results were validated using the Genetic Algorithm, NSGA2, and LINGO. The results indicated that the height of the sandwich panel and the thickness of the sheet had the most significant impact on the maximum force and panel weight. To this end, it is concluded that introducing a novel core design for the sandwich panel, utilizing a suitable Snap-Fitting method for attaching lattice parts rather than using a paste, and finally optimizing the core were the primary reasons for achieving this level of strength.