Structure Redesign of the Integrated Thermal Protection System and Fuzzy Performance Evaluation

Integrated thermal protection systems with both thermal protection and load-bearing capabilities are regarded as one of the most promising thermal protection concepts for future hypersonic vehicles. Yet improper design could cause the structure to be overweight and even fail prematurely during service. In this paper, the thermal-mechanical analysis model of integrated thermal protection systems is first established, and the thermal short and mismatch effects of typical corrugated web concept are studied. Three improved structural concepts are proposed. Thermal insulation capability and analyses of structural strength, stability, and stiffness are carried out on both the original and improved concepts. The results show that the web is a key component and that structural performance can be enhanced through web redesign. Then, a performance evaluation method is presented using the fuzzy decision-making model. Besides the aforementioned performance factors, two more factors with respect to structural complexity are considered. A comparison made between different concepts reveals that a structure with lightening holes is a promising concept that combines both structural efficiency and structural simplicity. The fuzzy decision-making model provides a comprehensive evaluation method by combining quantitative and qualitative information.