【作者】 哈跃；

【导师】 庞宝君；

【作者基本信息】 哈尔滨工业大学 ， 固体力学， 2010， 博士

【摘要】 随着航天事业的发展，空间碎片数量持续增加，空间碎片环境日益恶化，严重地威胁着航天器的在轨安全运行。对于毫米级空间碎片必须采取加装防护屏的措施予以防护。Whipple防护结构是最基本的空间碎片防护结构形式。目前，针对各种航天器的可靠性要求以及不同部件的功能需要，在Whipple防护结构的基础上发展了多种先进防护结构，如，多层冲击防护结构、填充Whipple防护结构和网格双防护屏防护结构等。这些防护结构普遍使用了先进的高强度纤维材料，如Kevlar、Nextel等。防护材料的选择和防护结构方案设计是开发先进防护结构的重要工作环节，优选先进防护材料、开发先进防护结构对保障航天器在空间碎片环境下的安全运行具有工程实用参考价值，了解和掌握纤维编织材料及其填充防护结构超高速撞击特性及其机理对于高速撞击动力学的发展具有重要的学术价值。玄武岩纤维也具有高强度、高模量的材料特性，从而具有作为防护材料的潜在优势。本文采用超高速撞击实验和理论分析相结合的技术手段，较系统地对国产玄武岩纤维布材料及其填充防护结构的超高速撞击损伤特性及机理进行了研究，分析了材料和结构在超高速撞击下的宏观效应与动态响应过程、织物细观编织结构、防护结构布局方案之间的相关关系。主要研究工作包括：首先，通过实验开展了玄武岩纤维布抗铝合金弹丸超高速撞击特性研究。利用哈尔滨工业大学超高速撞击研究中心的非火药驱动二级轻气炮高速弹丸发射装置进行了连续玄武岩纤维平纹编织材料-玄武岩纤维布的高速撞击损伤特性研究。通过对记录弹丸破碎过程的X-光闪光阴影照片的分析，除观察到了在高速撞击玄武岩纤维布时，铝合金弹丸后部产生的层裂破碎以外，还观察到了一种以前尚未见过到报道的弹丸前表面出现的局部沟状侵蚀损伤。利用数字显微镜观察到了溅落在玄武岩纤维布击穿孔周围的铝熔化后凝结成的球形颗粒，从而确定了本文实验范围内铝合金弹丸出现局部熔化的初始撞击速度。确认在本文实验范围内，在玄武岩纤维布与铝合金板面密度相同的条件下，相同直径的铝合金弹丸超高速撞击玄武岩纤维布时刚开始发生破碎时的临界破碎速度低于撞击铝合金板时的临界破碎速度，即玄武岩纤维布破碎铝合金弹丸的能力优于相同面密度的铝合金板。建立了玄武岩纤维布击穿孔直径方程、铝合金弹丸临界破碎速度方程和铝合金弹丸剩余速度方程。为将玄武岩纤维布用于空间碎片填充防护结构提供了依据。第二，建立了弹丸超高速撞击玄武岩纤维布动态过程的冲击动力学分析模型。通过将弹丸与玄武岩纤维布的弹、靶角色互换，将弹丸对玄武岩纤维布一次撞击的宏观分析模型转换为玄武岩纤维布细观尺度的纤维丝对半空间体（半无限体）弹丸多次冲击的细观动力学分析模型。第三，结合超高速撞击实验动态响应过程中弹丸的损伤行为和所建立的冲击动力学模型分析了玄武岩纤维布具有良好破碎高速弹丸能力的机理。根据叠代计算结果，分析了冲击压力的累积效应，并定性地分析了冲击温度的累积效应和累加效应导致弹丸熔化的机理。确认玄武岩纤维布的纤维丝对弹丸的撞击所产生的多源、多次冲击波是造成弹丸前部侵蚀损伤和后部层裂破坏的主要因素。最后，通过超高速撞击试验研究了玄武岩纤维布作为填充材料的填充防护结构的撞击特性。确定在本文实验范围内，在防护屏面密度相同条件下：涂环氧树脂胶玄武岩纤维/铝合金板填充防护结构的防护性能优于双层铝合金板防护屏防护结构，而与Nextel/Kevlar填充防护结构相当；涂环氧树脂胶玄武岩纤维布填充防护结构在玄武岩纤维布防护屏等间距分散布置情况下的防护性能优于涂环氧树脂玄武岩纤维布/铝合金板填充防护结构，并略优于Nextel/Kevlar填充防护结构；涂环氧树脂胶玄武岩纤维布填充防护结构在玄武岩纤维布防护屏等间距分散布置情况下的防护性能优于防护屏集中布置时的防护性能，涂环氧树脂胶玄武岩纤维布防护屏的布局方案对防护结构的防护性能有显著影响。并确认玄武岩纤维布作为填充材料在防护结构中提高防护性能的机理是，一方面，玄武岩纤维布防护屏通过拦截、破碎二次碎片云团中的碎片颗粒，降低二次碎片云团中的碎片速度，减轻了对舱壁造成的损伤；另一方面，通过自身材料的碎化或碳化，减轻了自身碎片对舱壁的损伤。玄武岩纤维材料作为一种先进的高强度纤维材料，同时还具有高模量的特点，具有抵御空间碎片超高速撞击的潜在优势。研究其在超高速撞击条件下的动态力学行为及其机理，掌握其超高速撞击条件下的防护特性数据，为该类材料在航天领域特别是在空间碎片防护领域的工程应用提供依据，对于发展性能优良的国产超高速撞击防护材料，发展新型的空间碎片防护结构，提高航天器抵御空间碎片超高速撞击的能力具有工程应用参考价值。更多还原

【Abstract】 Along with the development of space activity, the space debris population isgrowing continually, so the space debris environment is ever deteriorating. Thehazards to orbiting spacecrafts from space debris are aggravated increasingly. Themeasures must be taked to protect the spacecrafts against millimeter-grade spacedebris impacts. Whipple bumper shield is a basic type of space debris shielding. Atpresent, in accordance with reliability and function demand for different spacecraftsand components of all kinds, the high strength fiber materials such as Kevlar andNextel have been used in the advanced space debris shielding configurations suchas stuffed Whipple shields, multi-shock shields and mesh double-bumper shields. Itis a key link to choose the bumper materials and configurations of the shielding.Optimization of the advanced bumper materials and development of the advancedspace debris shielding can afford worthful references to ensure running safely inorbit in the space debris environment for spacecrafts. It is important to understandand grasp the highvelocity impact character and mechanism about materials andstructure of shielding for development of high velocity impact dynamic in thesphere of academic research.Woven of basalt fiber is a kind of fiber material too, having high strength andhigh modulus properties, and thus has a potential advantage for using in spacedebris shielding. The hypervelocity impact damage characteristics and mechanismof the domestic woven of basalt fiber material and its stuffed Whipple shieldingconfiguration were studied systematically, and the relationship of the hypervelocityimpact macro-effects of the material and the shielding with the process of dynamicresponse, micro-woven fabric structure and shielding configuration was analyzedby hypervelocity impacting tests and theoretical analysis method in present paper.The main research works include:First of all, Hypervelocity impact tests to study the damage properties ofwoven of basalt fiber against with space debris were carried out by the non-powdertwo-stage light gas gun facilities at Hypervelocity Impact Research Center inHarbin Institute of Technology. In addition to the spallation damage in the rear of aluminum projectile after hypervelocity impacting on woven of basalt fiber, theerosion damage in the front surface of the projectile that never be observed beforenow also can be observed. The initial velocity of aluminum projectile melting afterimpacting with woven of basalt fiber was determined according to the moltenaluminum spherical particles that splashed around the perforation by useing ofdigital microscope. It is confirmed that the fragmention-initation velocities ofaluminum alloy projectiles impacting on woven of basalt fiber are lower thanimpacting on aluminum alloy plate with the same areal density within the scope ofthe experiment. The perforation diameter equation of woven of basalt fiber, theresidual velocity equation and the fragmention-initation velocity equation ofaluminum alloy projectile were seted up. It provides a basis for woven of basaltfiber to be using in the stuffed Whipple shilding.Secondly，the impact dynamics model for analysing the dynamic process ofhypervelocity impact between woven of basalt fiber and aluminum projectile hasbeen built up. The macro-analysis model that aluminum projectile impact on wovenof basalt fiber only once was interchanged with the micro-analysis dynamic modelthat basalt fiberes impact on a half-space body (semi-infinite body) of the projectilerepeatedly by exchanging the role of aluminum projectile and woven of basalt fibertarget.Thirdly, according to the damage formes of projectiles impacting on woven ofbasalt fiber in hypervelocity impact testes and by using the micro-analysisdynamic model, the damage mechanismes of projectile were analyzed. Accordingto the iteration calculate results, the cumulative effect of the shock pressure wasstudied, and the melting mechanism of projectile caused by cumulative effect ofthe shock temperature was studied qualitatively. The analysis results showed thatthe main reasons of causing the spallation damage in the rear of aluminumprojectile and the erosion damage in the front surface of the projectile was themulti-shock on the projectile with the basalt fiberes at multi-poits.Finaly，the impact properties of woven of basalt fiber stuffed Whippleshielding were investigated by hypervelocity impact testes. The test results showedthat the protection property of woven of basalt fabric coated with epoxy resinadhesive/aluminum sheet stuffed Whipple shielding was better than doublealuminumsheet shielding, and equivalent to Nextel/Kevlar stuffed Whipple shielding with the same areal density within the scope of this paper tests. Theprotection property of woven of basalt fabric coated by epoxy resin adhesivestuffed Whipple shielding with bumpers laid in even space was better than withbumpers laid together, woven of basalt fabric coated by epoxy resinadhesive/aluminum sheet stuffed Whipple shielding, and Nextel/Kevlar stuffedWhipple shielding with the same areal density within the scope of this paper tests.The analysis results showed that the reinforce mechanismes of woven of basaltfabric used as the stuffed bumpers in the shielding were that woven of basalt fabricbumpers intercept and break the second debris cloud, and lower the velocity of thesecond debris cloud to reduce the damage of the rear wall, in addition, woven ofbasalt fabric bumpers are also breaked and carbonized to reduce the damage of therear wall caused by themselves as debris.Woven of basalt fabric is advanced fiber material with high-strength and highmodulus,and has evident advantages of protection against hypervelocity impactfrom space debris. The research on hypervelocity impact dynamic behaviorproperties and mechanisms to obtain the hypervelocity impact test data of woven ofbasalt fabric provided scientific basis for using this kind of high-strength fibermaterial in astronautical engineering and especially in the field of protectionengineering from space debris, and provided valuable reference for developing thedomestic protection material and new space debris shielding configuration withexcellent properties against hypervelocity impact.更多还原