This paper deals with a parametric identification technique, based on the c
onjugate gradient methods. As part of this research, compression tests are
performed on a XC48 steel (AFNOR norm 1048AISI), which is strain rate sensi
tive. Two kinds of specimens, tubular and cylindrical "dumbbell", are teste
d at different strain rates, from 10(-3) to 130 s(-1) and for impact veloci
ties ranging from 5 mm/min to 6 m/s. The parameters of the Johnson-Cook con
stitutive model are evaluated directly from the XC48 steel compression stre
ss-strain diagrams expressed in terms of true stress and strain measurement
s. These parameters are next used as input data for a FE crash simulation o
f the tubular specimen. Comparison with experimental results prove the vali
dity of the identified parameters. (C) Elsevier, Paris.