Thermostructural Design of a Flying Winglet Experimental Structure for the EXPERT Re-entry Test
Thermostructural Design of a Flying Winglet Experimental Structure for the EXPERT Re-entry Test
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DOI：
10.1115/1.3109242
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发表时间：
2009-07
影响因子：
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通讯作者：
M. Ferraiuolo;A. Riccio;M. Gigliotti;D. Tescione;R. Gardi;G. Marino
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文献类型：
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作者：
M. Ferraiuolo;A. Riccio;M. Gigliotti;D. Tescione;R. Gardi;G. Marino
在欧洲实验再入试验台（EXPERT）计划的框架内，为了提高对航天器从太空返回地球过程中发生的物理现象的理解，设计了一个飞行翼实验载荷，以评估超高温陶瓷（UHTC）在真实飞行气动热环境中的热力学行为和阻力。专家飞行小翼文章旨在重现这种情况。特别感兴趣的是UHTC小翼和EXPERT胶囊热保护系统之间的接口设计，因为在再入阶段会产生热应力。小翼与太空舱的固定是通过专用螺栓来实现的，这些螺栓必须能够承受在飞行的第一阶段（即起飞、上升和分离阶段）发生的机械载荷。采用ANSYS/Workbench有限元商业规范进行热结构设计；模拟考虑了瞬态热结构加载条件，陶瓷材料的弹塑性行为，以及胶囊热保护系统的温度相关弹塑性行为。在后处理阶段，通过以下两种不同的方法确定了UHTC关键区域。第一种方法是确定性的，包括应用最大应力准则，将节点上的应力与该节点上的温度相关强度进行比较。第二种方法通常用于弹性脆性材料，它是概率性的，包括应用Weibull-like破坏准则。模拟再入阶段的热分析和结构分析表明，所评估的最大应力和温度没有超过相应的极限。然后，确定了符合设计要求的结构，并对其热性能和力学性能进行了详细的讨论。
Within the framework of the European Experimental Re-entry Test Bed (EXPERT) Program, aimed at improving the understanding of physical phenomena occurring during the return of space vehicles from space to earth, the design of a flying winged experimental payload has been performed in order to assess the thermomechanical behavior and resistance of ultrahigh temperature ceramics (UHTC) in real flight aerothermal environment. The EXPERT flying winglet article is intended to reproduce such conditions. Particular interest covers the design of the interfaces between the UHTC winglet and the EXPERT capsule thermal protection systems since thermal stresses arise during the re-entry phase. The fixation of the winglet to the capsule is achieved by means of dedicated bolts that must tolerate mechanical loads occurring at the first stages of the flight, that is, lift-off, ascent, and separation stages. The thermostructural design is performed by employing ANSYS/Workbench finite element commercial code; simulations take into account transient thermostructural loading conditions, the elastic-fragile behavior of the ceramic materials, and the temperature dependent elastic-plastic behavior of the capsule thermal protection systems. In the postprocessing phase, UHTC critical areas have been identified by following two different approaches. The first approach is deterministic and consists in applying a maximum stress criterion, the stress at a node is compared with the temperature dependent strength at that node. The second approach, which is commonly employed for elastic-fragile materials, is probabilistic and consists in applying a Weibull-like failure criterion. Thermal and structural analyses simulating the re-entry phase have demonstrated that the maximum stresses and temperatures evaluated do not exceed their corresponding limits. Then, a configuration respecting all the requirements of the design has been identified, and its thermal and mechanical performances are discussed in detail.