| 1 | Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses显示文摘During the high-speed penetration of projectiles into concrete targets(the impact velocity ranges from 1.0 to1.5 km/s), important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions,may lead to obvious deviation of the terminal ballistic trajectory and reduction of the penetration efficien y. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differential Area Force Law(DAFL) method and semi-empirical resistance function, a finit differential approach was programmed(PENTRA2D) for predicting the terminal ballistic trajectoryofmassabrasivehigh-speedprojectilespenetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric noseabrasionoftheprojectile.Itsvalidationontheprediction of curvilinear trajectories of non-normal high-speed penetrators into concrete targets is verifie by comparison with available test data. Relevant parametric influentia analyses show that the most influentia factor for the stability of terminal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase. | H.Wu X.W.Chen Q.Fang X.Z.Kong L.L.He | 2015 | Acta Mechanica Sinica2015，31，4： | 4 |
| 2 | Modified spherical cavity-expansion model for projectile penetration into concrete targets显示文摘A modified spherical cavity-expansion model is developed in this paper.(1) We introduce a piecewise hyperbolic yield criterion suitable for pressure less than fc/3 to describe the mechanical behavior in the elastic region for the elastic-plastic response and modify the crack occurrence condition for the elastic-cracked-plastic response.(2) The hyperbolic yield criterion and a piecewise equation of state (EOS) are adopted for a better description of the plastic behavior of concrete material. Then, the modified model is validated by several projectile penetration tests in both the normal strength concrete (NSC) and ultra-high performance cement-based composite (UHPCC) targets. Finally, the hydrostatic pressure of the targets under rigid ogive-nosed projectile penetrations is found to be nearly within (0, 1.6 GPa), which usually exceeds the range that the shear strength-pressure test data covered. The influence of yield criterion on depth of penetration is discussed and it is recommended that the pressure should arrive at least 400 MPa in the related triaxial compression tests. | Y.Peng H.Wu Q.Fang X.Z.Kong | 2019 | Acta Mechanica Sinica2019，35，3： | 3 |
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