Study On Shear And Impact Mechanical Properties Of Aluminum Matrix Composite Foam-filled Circular Tube

With the continuous progress and development in the field of civil engineering,the requirements for safety performance of modern buildings are also rising.The explosion impact caused by leakage of gas from civil buildings and impact of ships,high-speed rails in accidental conditions,has attracted extensive attention from scholars at home and aboard in the field of civil engineering research.Thin-walled metal tube is a typical energy absorbing member,which has good deformation and energy absorption ability,but it is easy to generate large load fluctuations under the action of impact.In recent years,foam metal has been widely used in the field of civil engineering due to its excellent buffering and absorbing ability.Nowadays,material scientists use high-temperature and high-pressure experimental methods to combine fly ash hollow balls with ordinary aluminum materials.An aluminum-based composite foam material was successfully prepared,which has a significant increase in strength and energy absorption capacity compared to ordinary foam metal.At the same time,it is combined with a thin-walled metal tube to make it have better plastic deformation ability,so that it can be better applied to protection structures such as explosion,impact damage and other practical projects.In this paper,three kinds of aluminum-based composite foams with different average particle diameters of fly ash hollow spheres(150?m,200?m and 300?m)were prepared by experimental means.It is processed into a certain specification and filled into 6063 aluminum alloy circular tube,which forms an aluminum based composite foam filling pipe component.The mechanical properties and energy absorption properties under shear and transverse impact were studied by means of experiments and numerical simulation,the specific contents are as follows:(1)The quasi static double shear test of three kinds of aluminum based composite foam filled pipes with different average diameters was carried out by universal testing machine.The mechanical properties and energy absorption characteristics of the filled pipe components under shear action are quantitatively evaluated.Through the control variables,the influence of the average pore diameter of the microspheres in the core material and the thickness ratio of the casing diameter to the deformation failure mode,mechanical properties and energy absorption performance of the components was analyzed.(2)The transverse impact test of aluminum foam composite pipe was carried out by using drop hammer impact tester.The influences of mean pore size,impact energy and casing diameter ratio on the microstructure deformation failure mode,mechanical properties and energy absorption performance of the microspheres in the core material were studied.(3)The quasi-static shear and lateral impact numerical simulations of the components were performed using the numerical simulation software LS-DYNA.Comparing the experimental results of shearing and transverse impact,the parameters of the finite element model are adjusted and improved,so as to improve the accuracy of numerical simulation.On this basis,the test parameters were increased,and the model was used to perform variable parameter simulation analysis to study the effect of variations in the wall thickness of the metal casing on mechanical properties and energy absorption performance of the filled pipe members.