Investigation for the bending modes of a semi-circular pyramidal kagome sandwich structure and the bending load calculation

Lattice-based sandwich structures are being widely investigated to meet increasing demands for lightweight components. In the recent research works, lattice-based open cell structures have exhibited higher specific strength compared to closed cell structures, such as a honeycomb structure. Generally, a kagome structure is more effective than other lattice structures for compression and bending. In this work, cross-sections of the strut of pyramidal kagome (PK) structure are developed to strengthen the sandwich structure. A PK structure based on a semi-circular cross-section (SCC) was applied to the bending load calculation. The bending deformation modes of the SCC-based PK sandwich structure were investigated. The bending load was calculated when the PK sandwich structure was bent as stable shear mode and the equation could express the non-linear elastic characteristics during the bending process by applying the effective shear modulus of inner PK cores. The calculated bending load-deflection curve was compared with the bending load-deflection curve obtained by FEM. The tendency of the calculated bending load-deflection curve was similar to the FEM result.