| Foam aluminum has lots of excellent performances and extensive applications, whichmakes it an irreplaceable material in many field. Many efforts have been made to study it.The actual meso structure of the foam aluminum is very complicated, it performancedgeometrical inhomogeneity strongly. In this paper, the meso structure of foam aluminum wasanalyzed with image analysis method, the irregularity of its meso structure was statisticallystudied. Basing on the statistical distribution pattern of the meso structure, the meso structuregeometric model of foam aluminum was established to study the mechanical properties withFEM.First of all, the foam aluminum cross-sectional CT image was analyzed with theprofessional image processing software IMAQ to detect the edge of holes. A program codedwith Matlab was developed to trace the contour boundary and to fit the foam aluminum holeswith polygon and to get the geometric characters of foam aluminum meso structure. Thesegeometric characters was studied statistically, and the results shown that the distribution of theedge numbers, the areas, the equivalent radiuses, the size irregular degrees, the shape irregulardegrees of hole could be fitted with Weibull distribution.Secondly, based on the statistical distribution pattern from CT image, an random polygongenerating algorithm was developed with Monte Carlo method, and a Matlab program wascoded to establish the meso structure model of foam aluminum. The statistical analysis wascarried out to study the geometric parameters of the generated meso structure model. Theresults shown that the statistical distributions of the important geometric parameters of mesostructure models are similar to that of CT images.Finally, in the paper, the static and dynamic compression numerical simulation of mesostructure of foam aluminum are done, using ABAQUS finite element analysis software. Theelastic stages of stress-strain curves of different random models are basically coincide, butdifferent platform stages of meso structure models are different. It is unable to describe themechanical properties only using porosity, but the influence of meso structure has to beconsidered. In the case of dynamic compression, the law of the failure of deformation of thesame random model at different strain rates was analyzed, and the results showed that stress-strain curves at different strain rates have obvious difference. With the increase of strainrate, the platform stress is also increasing. In this paper, we draw the conclusion that thestress-strain curves of the same random model at different strain rates are sensitive to strainrate. |
