Analysis of the strain induced martensitic transformation in austenitic steel subjected to dynamic perforation

¹ Department of Continuum Mechanics and Structural Analysis, University Carlos III of Madrid, Avda. de la Universidad, 30, 28911 Leganés, Madrid, Spain
² Laboratory of Mechanics, Biomechanics, Polymers and Structures (LaBPS), National Engineering School of Metz (ENIM), Route d’Ars Laquenexy, CS65820, 57078 Metz Cedex 3, France
³ ENSAM-Arts et Métiers ParisTech, Laboratoire d’Études des Microstructures et de Mécanique des Matériaux LEM3, UMR CNRS 7239, 4 rue Augustin Fresnel, 57078 Metz Cedex 3, France

Abstract

An experimental and numerical analysis on the martensitic transformation in AISI 304 steel sheets subjected to perforation by conical and hemispherical projectiles is reported. Two target thicknesses are considered, 0.5 and 1.0 mm, and impact velocities range from 35 to 200 m/s. The perforation mechanisms are identified and the effect of the projectile nose-shape on the ability of the target for energy absorption is evaluated. Martensite has been detected in all the impacted samples and the role played by the projectile nose-shape on the transformation is highlighted. A 3D model implemented in ABAQUS/Explicit allowed to simulate the perforation tests. The material is defined through a constitutive description developed by the authors to describe the strain induced martensitic transformation taking place in metastable austenitic steels at high strain rates. The numerical results are compared with the experimental evidence and satisfactory matching is obtained. The numerical model succeeds in describing the perforation mechanisms associated to each projectile-target configuration analysed.