Research On Dynamic Mechanical Properties And Damage Pattern Of Hollow Microsphere/Al Alloy

Hollow microsphere/ aluminum alloy composites are relatively new materials that are being used increasingly in a range of applications due to their low density,high yield strength and excellent energy absorption capacity.Most of the applications are involved with dynamic loadings.Because of hollow structure and high strength of hollow microsphere, such composites can absorb more energy and reduce the damage from dynamic loading.So the research on dynamic mechanical properties and damage patterns of these composites has great values to engineering application.In this paper, the dynamic mechanical properties, energy-absorption capability of the Hollow microsphere/ aluminum alloy composites were investigated as well as the damage patterns of the hollow microsphere inside the composites. The investigation contents of this paper show below:Firstly,a self made PVDF is used to monitor the uniformity of stress on both sides of specimens in order to verify the experimental result. The dynamic mechanical properties of the two kinds of hollow microsphere/aluminum alloy composites and their matrix alloy was investigated by using SHPB experiments.Based on the experimental results,the strain rate effects of the composites and matrix alloy was investigated.Secondly,The microstructure of the specimen after compression was characterized by scanning electron microscopy, the damage patterns of the hollow microsphere was primarily studied. With the increasing of the decrement, the hollow microsphere appeared cracks along the meridians, gradually transitioned to the fragmentation of the equator and eventually collapsed.Thirdly, the dynamic mechanical properties of open-cell aluminum foam was investigated by using the SHPB experimental.Based on the experimental results,the energy absorption capability and energy absorption efficiency were discussed between hollow microsphere/ aluminum alloy composites and open-cell aluminum foam, the results indicate energy absorption of the composites is better than that of aluminum foam. The stress wave propagation mechanism in A3 steel/hollow microsphere/ aluminum alloy composites /2024 aluminum alloy tri-layered structure was investigated.Fourthly,a single-cell model and a approximate structure model of the composites was established, the dynamic compression process of single-cell and approximate model was finished by using the LS-DYNA explicit finite element software.Based on the numerical simulation result,the damage pattern of the hollow microsphere was investigated,the simulation result was agreement with the experimental result.In this paper, the dynamic mechanical properties, energy-absorption capability of the Hollow microsphere/ aluminum alloy composites ,as well as the damage patterns of the hollow microsphere inside the composites were investigated, the research has great values to engineering application.