Design Of Shear Thickener/Honeycomb Sandwich Protective Structure And Characterization Of Impact Dynamic Performance

Shear thickening Fluid(STF)is a kind of non-Newtonian fluid,that is,the viscosity of the fluid changes with the change of shear rate or shear stress.In the case of no or slight stress,STF shows good fluidity,but when the external force exceeds a certain critical value,the viscosity of STF system will increase sharply,even harden,with strong energy absorption and buffering ability.In this paper,STF and polypropylene honeycomb core are used as core material to design and prepare protective structure,and their low-speed impact resistance is explored.Firstly,STF with 50% starch and 55% starch was prepared by wet ball milling dispersion method,and its apparent phenomena and rheological properties were analyzed.Then,combined with STF and polypropylene honeycomb core,STF / honeycomb sandwich protective structure was prepared,and the specific manufacturing process was described.Secondly,this paper uses the Instron ceast9350 drop hammer impact test system to carry out low-speed impact test on the protective structure.Because the protective structure is a defensive equipment,stainless steel plate is placed under the protective structure in the impact test,and the maximum bearing capacity of the steel plate is one of the important indexes to measure the buffering and energy absorption effect of the protective structure.In the experiment,the bearing capacity time curve and energy time curve of the protective structure and steel plate under the conditions of different STF concentration,different impact speed and different thickness of honeycomb core are obtained;according to the test results,the influence of different parameters on the failure mode of the protective structure and the energy efficiency of buffer absorption is analyzed,as well as the failure process of the protective structure and the maximum bearing capacity of the steel plate Situation.Thirdly,based on the experimental data,using ANSYS LS-DYNA software establishes the finite element model,carries out the simulation calculation and analysis,compares the difference between the test results and the simulation results from the failuremode and the bearing capacity time curve,proves that the STF / polypropylene honeycomb protective structure can accurately reflect the impact force of the protective structure,and then studies the parameter change on the protective structure through the finite element model analysis The influence of energy absorption and deformation of each part.Finally,in order to better explore the performance of the protective structure,based on the accurate simulation of the finite element model,more external parameters are changed,different impact speed,different impact position and different impact angle are changed,and the impact of these factors on the energy absorption effect of the protective structure is analyzed.