Dynamic Response Of Thin-walled Cylindrical Shells Under Lateral Blast Loading

As the lightweight structure with high specific stiffness and high specific energy absorption,thin-walled cylindrical shells are widely used in military and civilian fields such as aerospace,automobile,high-speed trains and so on.The structure may undergo large plastic deformation even failure under the blast loading.Based on experimental research,the dynamic response of thin-walled cylindrical shell under lateral blast loading is studied with theoretical analysis and numerical simulation.The main work is as follows:(1)The experimental research is carried out to investigate the dynamic response of the cylindrical shells subjected to lateral blast loading with the ballistic pendulum system.The influences of the geometrical parameters,the TNT charge mass and stand-off distance on the final deformation mode and permanent mid-span deflection for thin-walled cylindrical shell is studied under13 conditions.The results show that three deformation modes of the cylindrical shells are obtained,including local plastic deformation,large inelastic deformation and tearing of the cylindrical shells.When the wall thickness of the structure,TNT mass and TNT stand-off distance are constant,the mid-spandeflection and deformation range increase as the diameter of the shells increases.Remaining the diameter of the shells,the cylindrical TNT charge mass and stand-off distance,the mid-span deflection and deformation range decrease as the wall thickness increases.The deformation area and the mid-span deflection of the cylindrical shell increase with the decrease of the TNT stand-off distance under the given geometric parameters of the cylindrical shell.When the TNT stand-off distance is constant,the deformation area of the cylindrical shell and the mid-span deflection decrease with the TNT charge mass decrease.(2)The dynamic response of a short thin-walled cylindrical shells under lateral blast loading is theoretically studied.The blast loading field and modal shape function are assumed,and the rigid-plastic beam model and modal analysis method on the ideal plastic foundation are used to study the large deflection of thin-walled cylindrical shell under lateral blast loading.The modal solution of deflection is given and analyzed the influence of the geometric parameters,impulse and different modal shape functions of the cylindrical shell on the mid-span deflection.The results show that the theoretical results of the permanent mid-span deflection are in good agreement with the experimental results,and the rationality of the theoretical model is validated.The impact of liner modal shape function and cosine modal shape function on the mid-span deflection can be neglected.The length-diameter ratio,wall thickness and impulse of the cylindrical shells have great influence on the mid-span deflection of the cylindrical shells.(3)The nine typical conditions in the experiment are simulated by using the finite element software ABAQUS.The impact of the structural parameters(diameter,thickness)and the loading impulse on the deformation mode and shock resistance is studied.The results show that the final deformation mode and permanent mid-span deflection of the cylindrical shell obtained by numerical simulation agree well with the experimental specimen results.When the structural diameter and impulse loading are constant,the mid-span deflection decreases as the wall thickness of the cylindrical shell increases.When the wall thickness and impulse loading are constant,the mid-span deflection increases with the increase of the diameter.With other parameters constant,and the mid-span deflection increases as the impulse loading increases.