Study On Buffer Energy Absorption Characteristics Of Variable Section Shell Filled With Foamed Aluminum Under High G Value

In the process of projectile penetration hard target,testing circuit in the projectile is subjected to high g value impact.In order to have a better buffering of testing circuit,this paper puts forward the geometric configurations of variable cross-section thin-walled metal shell.Multiple groups of variable cross-section thin-walled metal shells with different thicknesses and cylindrical shells which have the equivalent thickness are designed to protect the recording circuit single or multiple times under different half sine high g value acceleration loads,evaluating the cushioning properties by three aspects of the buckling mode,the specific energy absorption and the cushioning effect.And the buffer characteristics of the structure are verified by the drop weight test.In addition,the aluminum foam filled shell combines the advantages of the shell structure with small load fluctuation and the aluminum foam with deformation ability,small density,etc.Therefore,the maximization of the energy absorbed by the structure,and the minimization of the acceleration amplitude of testing circuit are considered as the target constraint function,the shell thickness and the foam aluminum density are considered as the optimization parameters.Based on the response surface method and the goal programming method,the multiobjective optimization of the buffer energy absorption characteristics of foam-filled variable cross-section thin-walled structures was carried out.Finally,the variable-section shell and the optimized foam-filled variable cross-section thin-walled structure are used as buffer elements to buffer the recording circuit in the case of projectile penetration of multilayer steel plates.It shows that during the whole buffer process,the buckling mode of the variable cross-section shell is an axisymmetric foldreduction mode that is buckled and deformed from one end with a smaller thickness,it greatly reduces the initial amplitude of the acceleration and avoids the dramatic increase in the magnitude of the acceleration caused by the compaction,and the energy absorption effect is relatively ideal.Therefore,it is of great significance for variable cross-section shell in multiple buffering.Multi-objective optimization takes into account a number of important indexes to evaluate the impact resistance of the structure,and it is of great significance to select a better buffer structure under certain load.