| The effect of the explosion on the surrounding objects can be regarded as a strong dynamic instantaneous load.Although it is only an accidental load,once the explosion occurs,it will have serious consequences for nearby buildings.How to adopt effective engineering protection technical measures to avoid the serious harm caused by the impact of explosion has become one of the hotspots in the field of civil engineering disaster prevention.The traditional methods of resistance to blast and impact mostly are used by increasing the strength of concrete and the size of the structural members and increasing the resistance of the engineering structures.For the past few years,lightweight energyabsorbing materials represented by foamed aluminum have been rapidly developed and become an auxiliary material of anti-blast structure and attracted much attention due to their excellent mechanical properties and energy absorption properties.In this paper,aluminum matrix composite foam material with high performance are focused,and they are combined with thin-walled metals to be the filled or sandwich structures,and the structures are used in a variety of anti-blast and anti-impact fields.First,three types of aluminum matrix composite foams with different hollow sphere sizes(150μm,200μm,and 300μm)were used as the research objects,and their mechanical properties and energy absorption properties under quasi-static load were studied by performing experiments.Then combined the aluminum matrix composite foams with the thin-wall tubes to make the foam filled aluminum tubes,and tested the compression performance with a universal material testing machine.Finally,the numerical simulations of the aluminum matrix composite foam sandwich cylindrical shell under blast load were performed by using ANSYS/LS-DYNA,and the resist blasting performance of sandwich cylindrical shell under blast load is analyzed.The specific researches are as follows:(1)Quasi-static compression performance tests were conducted on the aluminum matrix composite foam material specimens by using a universal material testing machine.The deformation and failure modes of the aluminum matrix composite foam material specimens with different particle diameters were studied,and the stress and strain curve of the material specimens were obtained,and its mechanical properties and energy absorption performance were analyzed.With the increase of the size of the hollow sphere,the compressive yield strength and energy absorption capacity of the material decreased.By using the least square method to fit,the constitutive equation of aluminum matrix composite foam under quasi-static load is given.(2)Quasi-static axial compression performance tests were conducted on the aluminum matrix composite foam filled aluminum tube by using a universal material testing machine.The deformation and failure modes of different filled aluminum tube specimens were compared and analyzed.The influence of each parameter on the mechanical properties and energy absorption performance of the filled aluminum tube was studied.And the crush force efficiency AE which is a new mechanical property index was introduced.The tests show that the filling of aluminum matrix composite foam greatly improves the mechanical properties and energy absorption performance of the foam filled aluminum tube.(3)Numerical simulations of the sandwich tubes with aluminum matrix composite foams core were performed,and the impact of the parameters such as foam thickness and shell thickness etc.on the mechanical properties and energy absorption performance of the foam filled aluminum tube was analyzed.It was found that there was a certain contradiction for each parameter on the performance of energy absorption and resistance to deformation of the sandwich tubes with aluminum matrix composite foam core.And comprehensive consideration should be taken and the main parameters should be determined according to the actual needs and then the structure should be optimized in the practical application. |
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