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Recently, there has been an increasing demand for foam materials for their ability to absorb energy under sudden impact. The main advantage of certain of these materials is their capability of providing also, high stiffness, high fire resistance, high thermal stability and thus even at very low density. Open-Cell Ceramic-like Foams (OCCF) are potential good candidates when they are covered by a ductile wrapping to avoid mass loss during the crushing. When used in shock absorber systems, OCCF s can be subjected to complex multiaxial stress states. Consequently, performing simple uniaxial compression tests with lateral confinement at different strain rates is not sufficient to model the mechanical behavior of such foam. It is also necessary to characterize it under multiaxial loadings. A thorough investigation of the mechanical behavior of Open-Cell Ceramic- Foams (OCCF) under multiaxial loadings was carry out using a Triaxial machine « Astree ». Two types of ceramic foam with densities of 120 and 250 kg/m3, respectively, were characterized. The OCCF foam showed a nearly isotropic behavior, with a slightly sensibility to the applied strain rate. Thanks to ex-situ X-ray Micro Tomography compression test, the mechanisms of degradation have been identified and correlated to changes in behavior that are noted on the stress-train curves. Failure envelopes of OCCF were constructed by using the strength values in uniaxial tension, uniaxial and multiaxial compression. The experimental yield surfaces were described well by the Deshpande Fleck failure criterion. The continuum constitutive model of Deshpande Fleck was improved by taking into account the variation of the plastic Poisson's coefficient to predict the radial expansion of the OCCF foams in its plastic domain. The extension of this model was implemented in the finite element code Ls-Dyna and used to identify the material parameters of both foams studied. The results of the numerical simulation obtained with this model show a good correlation to the experimental results.
