This paper deals with a parametric identification technique, basedon the conjugate gradient methods. As part of this research,compression tests are performed on a XC48 steel (AFNORnorm 1048AISI),Which is strain rate sensitive. Two kinds of specimens, tubular andcylindrical "dumbbell" , are tested at different strain rates, from10~-3 to 130s~-1, and for impact velocities ranging from 5 mm/min to6 m/s. The parameters of the Johnson-Cook constitutive model areevaluated directly from the XC48 steel compression stress-straindiagrams expressed in terms of true stress and strain measurements.These parameters are next used as input data for a FE crashsimulation of the tubular specimen. Comparison with experimentalresults prove the vali- dity of the identified parameters.
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