Analysis Of Dynamic Impact Response Characteristics Of Layered Gradient Lattice Sandwich Panels

The static/dynamic compression characteristics and blast resistance of layered density gradient pyramid sandwich panels are analyzed by combining experimental method and numerical simulation.Firstly,the multi-layer stainless steel pyramid lattice sandwich panels are designed and fabricated,and the density gradient between core layers is realized by changing the cross section dimensions of truss bar.Quasi-static compressive experiments are conducted for homogeneous and layered gradient lattice sandwich panels to obtain the reaction force-displacement curves using INSTRON material testing machine.By using the finite element software ABAQUS,the quasi-static compressive characteristics of five density gradient sandwich panels are numerically simulated.In addition,the effects of density gradient on the compressive performances of the panels are discussed.Secondly,the dynamic impact performances of the multi-layer lattice sandwich panels are analyzed experimentally by using the large-diameter Hopkinson pressure bar device.The deformation of the panels and the stress history of the incident bar during the dynamic impact process are analyzed.The ABAQUS software is applied to simulate the dynamic impact experiments of the panels,and the simulation method is validated by comparing the simulation with experimental results.The results obtained revealed that the middle facesheet of multi-layer lattice sandwich panels have significant effect on the deformation process of homogeneous panels.The deformation process of gradient structure only depends on the core arrangement of the relative density and not on the middle facesheet.Finally,the dynamic responses of multi-layer gradient pyramidal sandwich panels under air blast load are analyzed by finite element simulation.The Con Wep air blast model is applied to describe the specific blast loadings.The residual deflection on the center of the back facesheet and the support reaction on the boundary of panels are selected as the evaluation indexes of blast resistance of the sandwich panels.The blast resistances of the lattice sandwich panels with six different relative density ratios are analyzed,and the energy absorption of each component of the panels is discussed.The results indicate that the sandwich panels with increasing core density have the best blast resistance.The residual deflections and support reaction of the sandwich panel with increasing core density under different stand-off distances and different explosive charge are analyzed.The ORIGIN software is used to fit the empirical formula between the residual deflection of the back facesheet and the stand-off distances and the explosive charge.The corresponding conclusions are obtained,which can provide theoretical reference to the design of lightweight structure and engineering application.