Analysis Of Anti-Projectile Property Of Composite Sandwich Structure

Composite sandwich structures are used extensively in defense engineering,aeronautics and astronautics industry due to their extraordinary mechanical properties,which greatly contribute to reduce the structure weight and improve the anti-projectile property.Study of the ballistic performance and failure mechanism of composites under high velocity impact loading are important content of the survivability research of aircraft,which would lay a solid foundation for optimization of aircraft structure designing.Therefore,the damage analysis of composites under high velocity has been focused by many international researchers in the domain of composites mechanics.In this thesis,systemic studies including dynamic constitutive equation,engineering analyses and numerical simulations on ballistic performance and damage characteristics of composite sandwich structure under high-velocity impact are conducted.The main contents are as follow:(1)According to the composite sandwich structure studied in this issue,the dynamic mechanical damage models of three different materials,ie,metal material,ceramic material and composite material,are established respectively.(2)Considering the microstructure of composite sandwich structure,interface unit is introduced into the FEM model to stimulate the delamination of composite laminates.a 3D FEM model was established under ABAQUS software platform for analyzing the ballistic performance and damage characteristics of composite sandwich structure.Some valuable conclusions are obtained,which is valuable for the target design and material improvement.(3)3D numerical simulation models of high-velocity impact of composite sandwich structure are established according to the laying order of different materials,the thickness of composite sandwich structure and the ratio of thickness of different materials.The effect of the laying order of different materials,the thickness of composite sandwich structure and the ratio of thickness of different materials on the anti-projectile property of composite sandwich structure is studied.