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Abstract The crater depth and crack length of granite targets impacted by different velocity projectiles were studied with experimental and numerical methods. Five experiments were carried out by gas gun. The crater diameter，maximum penetration depth，distribution of cracks on target surface and the other destructive effects were obtained from the experiments at three different impact velocities. The distribution of inner cracks was attained with the help of cutting target normally impacted by the projectile at the velocity of 654 m/s. Nonlinear dynamic software Autodyn was used to simulate the penetration destructive effects of granite target. Johnson- Holmquist shock damage constitutive model(JH–2 model) and tensile crack softening model were coupled together to simulate the compressive and shear destructive effects in high pressure region，and the damage and propagation of radial tensile cracks generated by the principal tensile stress in low pressure region. Instead of traditional elements-deleting methods in FEM，the arithmetic of SPH was used and the parameter of damage was defined to describe the failure of compression and the cracks induced by shear and tensile failure. The simulation results about crater depth and crack length are consistent with the experimental ones. Based on numerical validated model parameters，serious numerical experiments were implemented；and formulae about crater depth and crack length of granite targets under the impact of different velocity projectiles were obtained. The method and the validated material model parameters used in this paper could be referenced by relevant experiments and simulations.
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Received: 25 October 2012
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2014, Vol. 33 
