Numerical approximation of the flexural properties for additively manufactured sandwich panels with a sheet-based TPMS core

Triply Periodic Minimal Surface (TPMS) structures as core structure enable multifunctional sandwich panels with nearly isotropic mechanical properties and possible media transport due to their channel-like topology. A new approach to extend laminar flow on aircraft wings for a more sustainable and energy-efficient aviation uses such sandwich structures as suction panels. Usually exposed to wing bending, evaluating the feasibility of suction panels requires a method for the numerical approximation of the bending behavior of TPMS-based sandwich panels. This study uses a novel numerical bitmap-based approach to compute the flexural properties based on the second moment of inertia and two common theoretical approaches from existing studies. To validate the theoretical approaches, this study compares them to experimental determined flexural properties, obtained through four-point bending tests on additively manufactured TPMS-based sandwich panels. The results show great agreement of the numerical bitmap-based flexural properties matching the experimental values with high accuracy, outperforming the two more common approaches at high relative densities. With the validation being successful, the bitmap-based approach enables the numerical estimation of the flexural properties by determining the second moment of area directly from the geometry of arbitrarily structured sandwich panels, eliminating the need for prior experimental tests or complex simulations.