最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

In order to improve the protective capability of spacecraft shielding configuration for hypervelocity impact of space debris, the Whipple-based shield configuration within the thin-plate bumpers of TiB2-based ceramic composites were manufacture(i.e. the monolayer bumper of ceramic plate, the double-layer bumper of ceramic/metal plate), the hypervelocity impact experiments were carried out on two-stage light-gas gun to compare the above novel bumpers with the typical aluminum alloy bumper under the impact velocity of 2.88 km/s ~7.32 km/s. The perforation characteristics of front bumper, the damage characteristics of rear wall and the structural characteristics of debris could were studied by combining the SEM fracture morphology and EDS elements distribution, especially, the relationship among the material properties and structure features of various bumpers, the formation process of debris clouds, the cratering mechanics of rear wall was discussed seriously. The study results showed that the monolayer ceramic bumper can effectively smash the projectile to smaller pieces in debris cloud, due to the impact kinetic energy of projectile fragments was distributed into the smaller particles of expanded debris cloud, the protective capability of the monolayer ceramic bumper exceed the typical aluminum alloy with equal areal density, moreover, the protective capability of the monolayer ceramic bumper was obviously promoted with the increasing impact velocity. On the other hand, for the double-layer ceramic/metal bumper, due to the difference in acoustic impedance between the ceramic and alumilun, the impact wace could cause the serious fracture in front ceramic plate as well as the curling deformation of rear aluminum plate, and the damge degree of ceramic/metal bumper increased in higher impact velocity. Because of the larger impact fragments and the smaller expanding bubble of the debris cloud, the protective capability of the double-layer ceramic/metal bumper is worse than the traditional aluminum bumper on the contrary. These primary results provide the theoretical and technological sopports for the space shielding application of TiB2-based ceramic composites.