热-力载荷下复合材料与金属结构连接的失效机理及连接设计

项目名称： 热-力载荷下复合材料与金属结构连接的失效机理及连接设计

项目编号： No.U1537101

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 江大志

作者单位： 中国人民解放军国防科技大学

项目金额： 45万元

中文摘要： 实现液体火箭发动机结构轻量化的重要途径之一是材料的轻量化。目前液体火箭发动机机架主要为金属结构。采用轻质高性能碳纤维复合材料代替机架金属杆架部件，可以显著减轻发动机重量。但复合材料构件与金属结构间的连接主要采用胶接或者“胶接+机械连接”的混合连接方式，连接界面成为最薄弱的部位，损害了复合材料的减重效果。本项目将针对液体火箭发动机推力支架大推力、高温、高频振动服役条件下复合材料构件与金属结构连接装配的相互作用开展研究，拟采用有限元分析和实验研究相结合的方法，研究高应力水平、热环境及振动疲劳载荷共同作用对复合材料-金属连接强度和可靠性的影响规律及失效机理；在此基础上从热匹配、刚度匹配、结构减重等角度开展复合材料-金属连接件及连接方案的优化设计研究，以减少连接赘重，提高连接效率和减重效果。

中文关键词： 碳纤维增强树脂复合材料；金属结构；连接设计；失效机理；热-力载荷

英文摘要： One of the most efficient way to fulfill weight saving of liquid rocket engine structure is employing lightweight materials. At present, most of the liquid rocket engine thrust truss is metal welding structure. Weight saving can be achieved obviously by replacing the metal pipe of thrust truss with carbon fiber reinforced polymer composite (CFRP ) or section bar connected by metal joints. CFRP components are connected with metal structure by glue joint or glue and mechanical joint. The interface between the CFRP and metal is the weakest area of the structure. The fundamental problem of the connection between composite component and metal structure under high stress level, high temperature and high frequency vibration conditions will be studied in this research. Finite element analysis and experimental study will be employed to investigate the relationship between the loading conditions of stress, temperature, vibration fatigue and the strength, reliability of joints. Failure mechanism of joints between the composite and metal materials under these loading conditions will be obtained by this way. Based on that, optimization design on joints and processing procedure will be carried out to promote the connection efficiency and to reduce the redundant weight. Matching problem of thermal properties, structural stiffness between the composite part and the metal structure will also be taken into account in this process.

英文关键词： carbon fiber reinforced polymer(CFRP);metal structure;joint design;failure mechanism;thermal-mechanical loadings