Dynamic failure and ejection characteristics of a periodic grooved Sn surface under unsupported shock loading are studied using a smoothed particle hydrodynamics method. An "Eiffel Tower" spatial structure is observ...Dynamic failure and ejection characteristics of a periodic grooved Sn surface under unsupported shock loading are studied using a smoothed particle hydrodynamics method. An "Eiffel Tower" spatial structure is observed, which is com- posed of high-speed jet tip, high-density jet slug, longitudinal tensile sparse zone, and complex broken zone between grooves. It is very different from the spike-bubble structure under supported shocks, and has been validated by detonation loading experiments. In comparison with that under supported shocks at the same peak pressure, the high-speed ejecta decreases obviously, whereas the truncated location of ejecta moves towards the interior of the sample and the total mass of ejecta increases due to the vast existence of low-speed broken materials. The shock wave profile determines mainly the total ejection amount, while the variation of V-groove angle will significantly alter the distribution of middle- and high-speed ejecta, and the maximum ejecta velocity has a linear corretation with the groove angle.展开更多
A simple abstract model of Eiffel is introduced, and its denotational seman-tics is defined using VDM style. A static analysis approach is presented to treatmultiple inheritance and renaming mechanism. Within the fram...A simple abstract model of Eiffel is introduced, and its denotational seman-tics is defined using VDM style. A static analysis approach is presented to treatmultiple inheritance and renaming mechanism. Within the framework of deno-tational semantics iatroduced in this paper, the key features of Eiffel, such asidentification, classification, multiple inheritance, polymorphism and dynamicbinding, can be adequately characterized.展开更多
基金Project supported by the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics(Grant No.U1530261)the National Natural Science Foundation of China(Grant Nos.11402032 and 11502030)the Science Challenge Project,China(Grant No.TZ2016001)
文摘Dynamic failure and ejection characteristics of a periodic grooved Sn surface under unsupported shock loading are studied using a smoothed particle hydrodynamics method. An "Eiffel Tower" spatial structure is observed, which is com- posed of high-speed jet tip, high-density jet slug, longitudinal tensile sparse zone, and complex broken zone between grooves. It is very different from the spike-bubble structure under supported shocks, and has been validated by detonation loading experiments. In comparison with that under supported shocks at the same peak pressure, the high-speed ejecta decreases obviously, whereas the truncated location of ejecta moves towards the interior of the sample and the total mass of ejecta increases due to the vast existence of low-speed broken materials. The shock wave profile determines mainly the total ejection amount, while the variation of V-groove angle will significantly alter the distribution of middle- and high-speed ejecta, and the maximum ejecta velocity has a linear corretation with the groove angle.
文摘A simple abstract model of Eiffel is introduced, and its denotational seman-tics is defined using VDM style. A static analysis approach is presented to treatmultiple inheritance and renaming mechanism. Within the framework of deno-tational semantics iatroduced in this paper, the key features of Eiffel, such asidentification, classification, multiple inheritance, polymorphism and dynamicbinding, can be adequately characterized.