Finite element modeling of the behavior of armor materials under high strain rates and large strains

• Main Authors: Polyzois, Ian, Polyzois, Ioannis
• Other Authors: Bassim, Nabil (Mechanical and Manufacturing Engineering)
• Language: en_US
• Published: 2010
• Subjects: high strain rate; adiabatic shear band; Johnson-Cook; Hopkinson Pressure Bar
• Online Access: http://hdl.handle.net/1993/3963

The objective of this research project was to simulate the behavior of armor metals at high strain rates and large strains, using the Johnson-Cook visco-plastic model, while incorporating the formation of adiabatic shear bands. The model was then to be applied to three armor metals, namely maraging steel 300, high hardness armor (HHA), and aluminum alloy 5083-H131; supplied by the Canadian Department of National Defense and tested in compression at the University of Manitoba. The Johnson-Cook model can accurately simulate the behavior of BCC metal (steels) up to a point of thermal instability. Conditions for complete shear failure in the model match closely to conditions at which adiabatic shear bands formed in specimens tested experimentally. The Johnson-Cook model is not quite valid for FCC metals, such as aluminum, where strain rate and temperature effects are dependent on the strain while in the Johnson-Cook model, these parameters are separable.