仿蜘蛛网结构柔性ZrOC/酚醛气凝胶材料力学设计与构筑

Hypersonic cruising/gliding aviation vehicles, which are considered as the representative of the high-end military equipment, are the commanding height where the countries compete for in the immediate future. Large maneuver and strong penetration stratagem requirement provide a great challenge for the thermal protection system of the aircraft fuselage. The traditional phenol formaldehyde (PF) aerogel is brittle and rigid, which makes it difficult to satisfy the complex thermal protection system requirement with curved surfaces. Therefore, how to make it flexible is a challenging and fundamental problem for the applications of aerogel. This project, firstly, provides an analysis on the relationship between molecular microstructure parameters and flexibility by using the molecular dynamics method, based on the theory of obtaining the flexible PF molecule structural formula by introducing the carbon-carbon double bond functional group at the para-position of the phenolic hydroxyl group. The mechanism of flexibilization of PF is revealed. Secondly, the ductile configuration of the ZrOC/PF aerogel with hierarchical and cobweb-like structure is designed. The nonlinear large deformation behavior and heat transfer mechanism of the flexible ZrOC/PF are illustrated based on the continuum damage mechanics and heat transfer models at the microscale. The relationship between structural parameters and thermal/mechanical performance is established. Finally, the flexible ZrOC/PF is prepared and its mechanical and thermophysical properties are experimentally characterized. The mapping relationship between the micro-structural parameters and thermodynamic behavior is established. This project will lay a solid foundation for the research and application of the novel material with flexibility on the thermal protection system of hypersonic aviation vehicles.

以高超声速巡航/滑翔飞行器为代表的高端军事装备是未来大国竞争的战略制高点。大机动强突防战略要求对飞行器机身热防护提出了严峻挑战。酚醛气凝胶作为传统热防护材料，刚脆性大，难以满足曲面复杂外形热防护需求。柔韧化是气凝胶研制应用面临的挑战性基础难题。本项目基于酚羟基对位引入碳碳双键获取柔性酚醛结构式的机制，采用分子动力学方法分析分子结构参数与柔韧性的关系，揭示酚醛柔韧化机理；设计具有多层级蜘蛛网仿生结构的ZrOC/酚醛烧蚀维形气凝胶，基于连续介质损伤力学模型和微尺度传热模型，阐明材料大变形与传热机理，建立结构参数与热/力学性能的映射关系；开展柔性ZrOC/酚醛气凝胶材料制备及力学、热物理性能表征研究，揭示材料微结构与性能的对应关系。本项目将为高超声速飞行器热防护系统新型柔韧性防隔热一体化材料研制和应用奠定基础。

以高超声速巡航/滑翔飞行器为代表的高端军事装备是未来大国竞争的战略制高点。大机动强突防战略要求对飞行器机身热防护提出了严峻挑战。酚醛气凝胶作为传统热防护材料，刚脆性大，难以满足曲面复杂外形热防护需求。柔韧化是气凝胶研制应用面临的挑战性基础难题。本项目基于酚羟基对位引入碳碳双键获取柔性酚醛结构式的机制，采用分子动力学方法分析分子结构参数与柔韧性的关系，揭示酚醛柔韧化机理；设计具有多层级蜘蛛网仿生结构的ZrOC/酚醛烧蚀维形气凝胶，基于连续介质损伤力学模型和微尺度传热模型，阐明材料大变形与传热机理，建立结构参数与热/力学性能的映射关系；开展柔性ZrOC/酚醛气凝胶材料制备及力学、热物理性能表征研究，揭示材料微结构与性能的对应关系。本项目将为高超声速飞行器热防护系统新型柔韧性防隔热一体化材料研制和应用奠定基础。在基金的支持下，在《Journal of the European Ceramic Society》《Ceramic Society》、《Composites Structures》、《材料导报》等期刊发表学术论文12篇，其中SCI检索论文8篇，EI检索论文4篇，多次参加国际、国内学术论文，并做分会场邀请报告。协助指导博士研究生1，硕士研究生2人。