载人航天器密封舱结构超高速撞击易损性

Vulnerability of pressurized cabin for manned spacecraft under hypervelocity impact

摘要:

载人航天器密封舱是载人航天任务航天员在轨安全工作和生活的重要保障,为掌握载人航天器密封舱防护结构易损特性、准确获取密封舱防护结构易损性模型,基于二级轻气炮,开展了某载人航天器玄武岩/芳纶纤维填充式防护结构试验件撞击试验,获取了3类防护结构试验件撞击极限直径,完成了防护屏、填充层和舱壁结构撞击损伤特性分析,结果表明,相同撞击速度下,防护屏穿孔孔径与弹丸直径正相关,玄武岩/芳纶纤维填充层对弹丸和碎片云有较强破碎作用和能量分散作用,降低对密封舱结构损伤,沿主撞击方向碎片云能量是引起舱壁结构花瓣形裂纹穿孔的主要因素。针对试验数据,采用遗传算法和多元线性/非线性回归方法对NASA Christiansen方程、W-S穿孔方程进行修正,提升了预示精度,其中总体预测率从59.1%提升到100%,安全预测率从81.8%提升到100%,准确建立了适用于中国某大型载人航天器玄武岩/芳纶纤维填充式防护结构的撞击极限经验方程和穿孔经验方程等两类易损性模型,为在轨任务风险工程评估提供依据和奠定基础。

Abstract:

The manned spacecraft capsule provides a critical safeguard for the safe work and life of astronauts during space missions. To understand the vulnerability characteristics of the pressurized cabin structure and obtain an accurate model of its vulnerability, impact tests of the basalt/aramid fiber-filled Whipple shields were carried out based on two-stage light gas guns. Ballistic limit diameters of three types of test pieces were obtained, and the impact damage characteristics of the bumpers, filling layers and rear wall were analyzed. The results showed that the hole size of the bumper was positively related with the diameter of the projectile. The basalt/aramid fiber filling layers had a strong crushing and energy dissipation effect on the projectile and the debris cloud, which reduced the damage to the pressurized cabin structure. The energy of the debris cloud along the main impact direction was the main factor causing the petal-shaped crack perforation of the rear wall. Based on the test data, the NASA Christiansen equation and the W-S hole size equation were modified using a genetic algorithm and a multivariate linear/nonlinear regression method, improving the prediction accuracy. The overall prediction rate increased from 59.1% to 100%, and the safety prediction rate increased from 81.8% to 100%. Two types of vulnerability models, including the impact limit equation and the hole size equation, were accurately established for the basalt/aramid fiber filled structure of a certain large Chinese manned spacecraft, providing a basis for the risk engineering assessment of on-orbit missions.