Strain Rate Dependence of the Spall Strength of Steels

The data on the dynamic (spall) strength for more than 30 steels are reported.These data were interpreted in tenns of the fracture mechanics.The experimental data are interpreted in terms of the energy-based spa11 theory which predicts the dependence of the spall strength on the strain rate in the spall plane.Even if most of the tested steels exhibit the agreement with this theory there are some exceptions .In order to explain this disagreement a modification of the theory mentioned above bas been suggested.The obtained model predicts the observed steel behaviour.Wsumk.L'ttude mentiome les valeurs de la resistance dynamique (d'kaillgc) pour plus que 30 aciers.Ces valeurs out kt6 interpret& sur les bases de la mhnique de la rupture.Les rcsultats dcs espkricnccs son1 interpretks par la thhrie Cnergetique d'kaillage prtdiquant la dCpendance de la resistance d'ccaillge et de la vitesse de dkformation sur le plan d'ecaillge.Malgre que la plupart des aciers examines montrent I'accord avec cene thbrie, ily a aussi des exceptions.Dans I'intention d'eqliqucr ces desaccords, une modification de la thhrie mantiounke est propode dans at ourage.Le modele obenu predique avcc succds le comportement des acien examines pendant l'kaillage.