Adiabatic Shear Failure Behavior of 30CrMnMo Steel under Pulse Stress Impact.

In order to study the adiabatic shear failure behavior and evolution characteristics of 30CrMnMo steel under pulse stress impact, a split Hopkinson pressure bar was used to conduct an axisymmetric cap shaped specimen for impact shear experiments. The shear failure evolution and temperature distribution in the shear zone under different incident pulse stress loads were numerically simulated using LS-DYNA dynamic finite element software. The results indicate that the adiabatic shear failure of the cap shaped specimen is related to the specific impulse of the pulse stress. For cap shaped specimen of 30CrMnMo steel, the specific impulse of pulse stress corresponding to the adiabatic shear failure is approximately constant. In numerical simulation, when the grid size is smaller than the width of the shear band, the local temperature rise of hot spot within the shear band can be effectively simulated. The evolution of adiabatic shear instability is characterized by simultaneous propagation from the corner of the shear zone to the center, and the materials inside and outside the shear zone mainly undergo two stages: uniform shear deformation and rapid expansion of instability. [ABSTRACT FROM AUTHOR]