Numerical Simulation Of Dynamic Mechanical Response Of Aluminum Foam Sandwich Structures

Aluminum foam is a new type of low-density material;due to its unique surface effect,volume effect,and excellent mechanical,electrical,acoustic,and thermal properties offer excellent potential for lightweight construction,energy absorption,and thermal management.Using aluminum foam as the core layer,steel,aluminum alloy,and other materials as the panel,it makes an aluminum foam sandwich structure through a specific process.It has the excellent energy absorption characteristics of aluminum foam and the high strength of steel and other metals.Due to its lightweight and good impact resistance and energy absorption characteristics,it has been widely used in fields with high energy absorption protection requirements,such as aerospace and automotive.In practical applications,the aluminum foam sandwich structure is often subject to shock loads such as impact and explosion,so studying its mechanical properties under shock loads is critical.However,the current research on the aluminum foam sandwich structure mainly aims to research the sandwich panel at ambient temperature.The study of the sandwich shell under impact load and the study of the dynamic mechanical properties of the sandwich structure at different temperatures are not very comprehensive.Based on the above,this paper adopts the finite element method combined with solid impact mechanics,using ANSYS/LS-DYNA numerical simulation software,the mechanical properties of aluminum foam sandwich panels,sandwich cylindrical shells,and sandwich shallow shells under impact load were compared and studied.Moreover,the dynamic mechanical properties of the aluminum foam sandwich cylindrical shells at different temperatures were also studied.The specific work and results are as follows:(1)The effect of the shape of the aluminum foam sandwich structure on its mechanical properties was studied.The energy absorption efficiency and overall deformation of sandwich panels,sandwich cylindrical shells,and sandwich shallow shells under the same impact load were studied.The results show that the energy absorption performance of the sandwich shells is better than that of the sandwich panels,and the overall deformation is less than that of the sandwich panels.The influence of increasing panel thickness on the two types of sandwich shell studies is based on this basis.The conclusions describe that increasing the panel thickness will significantly reduce the structure’s energy absorption efficiency and deformation.Finally,the effect of single-and double-layer structure on the impact resistance of sandwich shells was studied when the total thickness of the sandwich structure was unchanged.The results show that compared with the single-layer structure,the energy absorption efficiency,overall deformation,and contact force between the projectile and structure of the double-layer structure will be reduced.(2)The effect of temperature on the dynamic mechanical properties of the aluminum foam sandwich cylindrical shell was studied.The dynamic mechanical properties of the aluminum foam sandwich cylindrical shells from-50 °C to 300 °C were studied.The results show that at temperatures ranging from-50°C to 300°C,the energy absorption of the sandwich cylindrical shells does not change significantly as the temperature increases.However,the deformation of the center point of the back panel and the structure’s overall deformation will increase with the increase in temperature,and the impact resistance of the entire structure will decrease.Finally,the failure mode of the aluminum foam sandwich cylindrical shells is analyzed.The results show that under the projectile’s impact,the sandwich cylindrical shell mainly undergoes shear failure at-50°C,25°C,and 300°C.The upper and lower panels of the sandwich cylindrical shell are mainly the shear failure,and the aluminum foam core layer is the failure by compaction and collapse at the same time as the shearing failure occurs.