Sandwich panels have complex structures and mechanical behavior. To optimally design these structures, it is necessary to understand their mechanical behavior. In the sandwich panel design process, performing numerical simulations faces many difficulties in terms of calculation time as well as model building time. This study focuses on building an equivalent 2D finite element FEM model to replace the 3D model of a double wall corrugated cardboard plate under tension. The accuracy of the proposed model is confirmed by comparing the results between the 3D and 2D models. This model can be used to calculate corrugated core sandwich metal panels.