Research On The Compression Mechanical Behavior Of The Cenosphere Aluminum Maerix Composite Foam Material

The aluminum maetrix composite foam material is a excelent energy absorptionmaterial which has widely attracted people’s attention in recent years. This materialhas many superior properties such as low density, high porosity, high specificstrength, specific stiffnessand excellent energy-absorption capacity. It has innatesuperiority when bearing the dynamic loading in practical application. This materialis composited by the fly ash Hollow Spheres and the Aluminum-matrix skeleton.The composite foam material has high failure strength and satisfactorycomprehensive mechanical properties due to the enhancement of the special hollowsphere structure and the hollow spherereinforcement. Therefore, the aluminummaetrix composite foam material could absorb a large quantity of energy and reducethe damage to structures under the blast load and the impact load. It has veryimprotant meaning to investigate the dynamic mechanical behavior and theenergy-absorption characteristic of the aluminum maetrix composite foam materialunder high strain rate.This thesis performs edin-depth study of the dynamic mechanical behavior, thedamage evolution law of the composite material matrix and inner hollow spheres,buffer energy absorption characteristic of the aluminum maetrix composite foammaterial with two pore diameters,80μm and150μm, under low, median and highstrain rate gradient, respectively. The main research are as follows:(1) This paper uses the quasi-static compress test technology, axial drophammer impact test technologyand split hopkinson pressure bar(SHPB) testtechnology to investigate the dynamic mechanical behavior and energy absorptioncharacteristic of the aluminum maetrix composite foam material under low, medianand high strain rate gradient, specially analyse the law of the influence of the strainrate and the pore diameter of the hollow sphere on the dynamic mechanical behaviorof the composite foam;(2) This paper uses the large finite element software LS-DYNA to simulate theaxial drop hammer impact test and SHPB test, further verify conclusions reached bytests;(3) This paper employs the scanning electron microscope (SEM) technology tostudy the deformation mode and the damage failure mechanism of the cell in thephoto through polishing the cross section surfaceof compressed samples;(4) This paper analyzes results of the quasi-static compress test, axial drophammer impact test and SHPB test, thoroughly research problems such as how toassess the energy absorption capacity of specified aluminum foam,in which work condition th eenergy absorption capacity of the aluminum foam could be fullyyielded, the influence on the energy absorption capacity of factors like the matrixmaterial, relative density, cell pore size and the strain rate;(5) This paper bulids cell models of the open-cell and closed-cell aluminumfoam using the LS-DYNA large Finite Element software based on photos capturedby the SEM, respcetively, and study the deformation mode and the damage failuremechanism of the inner cell in the aluminum foam;In summary, the dynamic mechanical behavior of the aluminum maetrixcomposite foam material with two pore diameters,80μm and150μm, under low,median and high strain rate gradient is obtained. The damage evolution law of thebufferenergy absorption characteristic of the composite material matrix and innerhollow spheres is investigated in this paper. All of the work have some referencevalue for the engineering application of the aluminum maetrix composite foammaterial.