N型防护结构的试验与仿真研究

在不增加空间碎片防护结构整体尺寸和质量的情况下，基于防护结构在斜撞击条件下弹道极限高于正撞击条件下弹道极限的特性，研究了一种将3层平行铝板结构的中间层进行倾斜的N 型防护结构，采用超高速碰撞试验和三维SP H 数值仿真方法，定量对比了N型防护结构与相同面密度3层平行铝板结构的防护性能。研究结果初步证实，在正撞击情况下，倾斜的中间层具有提升结构防护性能的作用。

Test and simulation of N-shape shield configuration

In order to improve the performance of the shield without increasing its weight or size,an N-shape configuration with an oblique middle wall is proposed in the study based on the fact that the ballistic limit of oblique impact is higher than that of normal impact.The performance of the N-shape configuration and a parallel triple-wall configuration with the same areal density are compared and analyzed by 3D numerical simulation （SPH ）and hypervelocity impact tests.The hypervelocity impact tests under different impact conditions have been carried on.The test results,which are achieved under the condition that the diameter of projectile in the normal impact is 4.0mm and the impact velocity is about 3.0km/s,indicat that there is little difference of damage on rear plates between the two configurations.In another normal impact test with a projectile diameter of 5.5mm and an impact velocity of 4.8km/s,the damage difference become considerable,and there is a perforation with a diameter of 2.0mm in the rear plate of the triple-wall configuration but no perforation happens to the rear plate of the N-shape configuration under the same condition.Simulation with the same impact parameters as the tests is carried out.The results show that the critical proj ectile diameter of the triple-wall configuration is about 4 .1 mm and that of N-shape configuration is about 4.3mm,when the velocity of the normal impact is 3.0 km/s.The critical projectile diameter of triple-wall configuration is about 5.5mm and that of N-shape configuration is about 5.9mm under the normal impact with a velocity of 4. 8km/s.The simulation results are in accordance with the test results.These results showed that the perform-ance of N-shape configuration is improved by the oblique middle wall under the condition of nor-mal impact espercially with a higher velocity.