Experimental And Simulation Of Quasi-static Compression Mechanics For Spherical Porous Aluminum Foam/Polyurethane

Aluminum foam is a new kind of foam metal material with special cell structure,low yield strength and large compressive strain.It has good mechanical properties and energy absorption properties,and is widely used in machinery,transportation and aerospace,etc.The spherical open-cell aluminum foam has both the advantages of open cell aluminum foam and closed-cell aluminum foam.It combines the advantages of both of them,but overcomes the shortcomings of each of them,so that it is a aluminum foam material with better performance.By filling polyurethane into open-cell aluminum foam,a novel material in which aluminum is interwoven with a viscoelastic polymer material is obtained,which will greatly improve the mechanical properties of the aluminum foam and to meet the needs of structural and functional integration of materials,so that it can be applied to more fields.In order to investigate the mechanical properties of the open-cell aluminum foam and spherical open-cell aluminum foam/polyurethane(SPAF/PU)composites,the following studies were performed:(1)The SPAF/PU composites were prepared by filling the open-cell foamed aluminum with molten polyurethane under pressure,and the filling rate reached above 95%.The quasi-static uniaxial compression experiments on aluminum foam and SPAF/PU composites with different pore sizes and different relative densities were carried out.The stress-strain curves of the two materials were obtained,and the deformation mechanism was studied.The results show that for the two materials,the larger the pore size and the higher the relative density,the higher the compressive strength of the material,the greater the stress of the plastic plateau and the greater the energy absorbed in the same strain range.In addition,the amount of polyurethane filled also has an effect on the mechanical properties of the material.(2)By improving the Sherwood-Frost constitutive model,a quasi-static constitutive equation that considers the influence of relative density and shape function on the composite material is established.The fitting of quasi-static compression experimental data was performed by MATLAB and all the parameters of the constitutive model were obtained.The fitting results show that the established constitutive equations have a good fitting effect,which paves the way for numerical simulation of the quasi-static compression mechanical properties of foam aluminum and SPAF/PU composites.(3)A three-dimensional model of spherical open-cell aluminum foam and spherical closed-cell aluminum foam was established respectively.By programming the algorithm,a random model with adjustable aperture and number of layers was generated.Compared with the commonly used simplified foam aluminum model,the established model restores the structure of the aluminum foam in used in the experiment more accurately.Compared with the CT scan modeling,the modeling process is simple and the cost is low.(4)By ABAQUS finite element analysis software,the quasi-static compression numerical simulations of spherical open-cell aluminum foam and SPAF/PU composites were performed using the established quasi-static compression constitutive equations of the materials.Comparing the experimental and simulation results,the correctness and validity of the three-dimensional model of the sphere open-cell aluminum foam established were verified.At the same time,the correctness of the constitutive model adopted was verified.This study provides methods and basis for numerical simulation of spheres open-cell aluminum foam and SPAF/PU composites.