Identification of Armox 500T steel failure properties in the modeling of perforation problems

Abstract

The paper presents a description of fracture surface development for Armox 500T steel in the space of triaxiality and the Lode parameter. The aim of this work was achieved with the application of the proposed coupled experimental-numerical procedure. Firstly, an appropriate set of basic tests was proposed and performed with experimental data acquisition, and then simulated numerically in equivalent conditions. Subsequently, the combination of experimental and numerical results allowed the fracture surface of Armox 500T to be built with the biharmonic spline interpolation method. The obtained initial fracture surface was calibrated in an iterative procedure based on the results of quasi-static perforation tests with pointed, flat and hemispherical punches. Finally, the predictive capability of the developed fracture surface was confronted with other failure models disclosed in the literature for Armox 500T. The proposed failure model provided a response that was found to be qualitatively and quantitatively superior to the other models because it accurately reflected the experimentally observed perforation patterns and force histories. On the basis of the character of the designed surface, it can be stated that Armox 500T armor steel demonstrates high sensitivity of fracture properties to both triaxiality and the Lode parameter. Keywords: Fracture mechanics, Perforation, FEM, Armox 500T, Triaxiality, Lode parameter