MULTIAXIAL PHENOMENOLOGICAL COMPRESSIBLE CONSTITUTIVE PARAMETERS FOR CLOSED-CELL ALUMINUM FOAMS

A three-dimensional (3D) finite element model for real closed-cell aluminum foam specimen was constructed by employing the microfocus X-ray CT system, 3D reconstruction program and the commercially mesh generation program. By changing the boundary conditions of the 3D finite element models for real closed-cell aluminum foam specimen, eleven various stress states including uniaxial (sides coupling), hydrostatic and proportional compression loading were applied for analysis. The yield surface parameters of three compressible elasto-plastic constitutive models were obtained from numerical results. In testing hydrostatic compression, the crushable foam model with isotropic hardening in ABAQUS showed very serious deviation, especially at large strain levels. Chen-!-Lu constitutive models lightly underestimated the hydrostatic yield stress. The present volumetric hardening model was seem to give accurate predictions for both uniaxial and hydrostatic compressions.