Theoretical Study and Verification of the Mechanical Properties of Concave Honeycomb Structures Based on Additive Manufacturing

This paper focuses on the internal honeycomb structure of flexible skins for morphing aircraft, specifically targeting a unique concave honeycomb structure. By selecting specific honeycomb cells and simplifying their cell walls to beams, the equivalent elastic modulus and shear modulus were derived using the principle of virtual work. The cell was also simplified to an orthotropic plate, and the equivalent bending stiffness was derived using the principle of equivalent deformation energy. Using additive manufacturing methods and photosensitive resin materials, a series of honeycomb structure test pieces were manufactured and subjected to mechanical performance tests. The stress–strain curves and load-deflection curves of the honeycomb structures were obtained, and the equivalent elastic modulus, equivalent shear modulus, and equivalent bending stiffness were calculated from the experimental data. The theoretical values of the equivalent mechanical properties were compared with the experimental values, with errors of 4.38%, 16.67%, and 15.47% for the equivalent elastic modulus, equivalent shear modulus, and equivalent bending stiffness, respectively. Finally, the causes of the errors were analyzed, and this method has significant value for the application of such honeycomb structures.