Study On Mechanical Properties Of Sandwich Structure With Multi-layer Variable-scale Honeycomb

Honeycomb sandwich structure has been widely used in aerospace,mechanical engineering,ship and other fields due to its light weight and high strength,excellent heat insulation and sound insulation performance.At present,the research and application of honeycomb sandwich structures are mainly based on single-layer honeycomb sandwich panels,but there are few reports about the research on multi-layer honeycomb sandwich structures with variable scale.This paper will take the three-layer honeycomb sandwich structure as an example,and adopt the method of combining theoretical analysis and numerical simulation to study and discuss the mechanical properties of multi-layer honeycomb sandwich structure,and analyze the law of mechanical properties changing with structural parameters,which provides reference for the research and design of multi-layer honeycomb with variable scale.In the first chapter,the research status of honeycomb sandwich structure is summarized,if's equivalent mechanics parameters,flat compression property and dynamic impact property are summarized and discussed.In the second chapter,based on the theoretical model of the single-layer honeycomb sandwich structure,the equivalent modulus of the three-layer honeycomb sandwich structure is derived by using the equivalent theory,and it is functions of the thickness of each core layer,the elastic modulus out-of-plane and in-of-plane core layer,the thickness of the panel and the elastic modulus of the panel.The Z-direction elastic modulus of multi-layer honeycomb structure can be used as the prediction of the subsequent finite element model.In the third chapter,the finite element model of three-layer honeycomb sandwich structure is established by using ABAQUS finite element software.Then based on the comparison between the simulation results of this model and the theoretical results in the previous chapter,the theoretical prediction results of mechanical properties of multi-layer honeycomb structure are verified.And the influence of the parameters of the three-layer honeycomb structure was studied,the results show that the equivalent elastic modulus of the honeycomb core decreases with the increase of the proportion of the middle layer and the increase of the cell size.In the fourth chapter,based on the finite element model established in the previous chapter,the dynamic mechanical properties of the three-layer-honeycomb sandwich structure are analyzed,the performance of the structure with different core structure parameters and different impact velocities is discussed respectively:the impact velocity is correlated with the stress of the platform while the proportion of the middle layer mainly affects the compaction stage of the deformation process.In addition,the impact of warhead shape on the penetration resistance of the multi-layer honeycomb sandwich structure is mainly manifested as that the flat projectile will consume more energy during the penetration process;The higher impact velocity causes the structure to absorb more impact energy.