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.