Design And Compression Energy Absorption Of Kagome Lattice Sandwich Structure

Lightweight sandwich structures with lattice cores generally consist of the rigid faceplate and light cores.These structures have high specific strength and specific stiffness,as well as heat insulation,noise reduction and shock absorption,due to the integration with structural,material and functional design.It is regared as the most promising new generation lightweight structure.In this thesis,3D printing technology is employed to prepare the sandwich structure with three-dimensional Kagome periodic cell,which has the characteristics of integrated preparation and rapid prototyping.Based on the experimental and numerical analysis of the compression behaviors and energy absorption characteristics of the lattice sandwich structure,the structural core configuration is optimized to improve the mechanical properties.The single-layer Kagome lattice sandwich structures with different relative densities are designed and fabricated,and the compression properties are tested and numercially simulated.The effects of cell geometric parameters,such as the diameter and inclination angle of the core-bar,on the compression property,deformation process and failure mode of the structure,revealing the structural damage mechanism.In addition,the compressive energy absorption characteristics are characterized,and the post-compression recovery after densification is analyzed.The compression property of double-layer Kagome lattice sandwich structure is studied.According to the deformation behaviors,two modified configurations of double-layer structure,network-and face-reinforced,are proposed.The effects of cell geometric parameters on the compression behavior,failure mode and energy absorption characteristics are discussed,exploring the strengthening mechanism.In addition,the finite element method is used to effectively describe the structural deformation process and the transformation of failure modes.The compressive capacity and deformation tolerance of lattice cores are further improved by filling polyurethane foam.The compression behavior and energy absorption characteristics are conducted.The filling reinforcement and the effect of cell geometric parameters are explored to reveal the structural failure mechanism.The deformation recovery and secondary compression behavior of the structure after densification are analyzed.The filled structure has excellent anti-compression energy absorption characteristics and cyclic bearing capacity.