Ti/Cf/TPI混杂层板热力耦合作用下的变形规律及成形损伤生成演化机理研究

Ti/Cf/TPI hybrid laminates, as an important member of the 4th generation fibre metal laminates (FMLs), is becoming an important structural material of new generation of aircrafts such as aerospace plane and supersonic transport. But now, we are still unable to control precisely for the structure and performance since deformation characteristics have not been understood systematically. Defects such as fibre breakage, matrix cracking and delamination are easy to occur during forming process..This project takes Ti/Cf/TPI hybrid laminates as the research object. Firstly, the influence of structures on deformation mechanism will be studied systematically. The corresponding relation between structure and performance will be explored from nanoscale, mesoscale and macroscopic. Then, the deformation characteristics of components and interfaces under different forming conditions will be mainly discussed. Finally, the generation and evolution mechanism of damage defects will be studied from macro- and micro-perspective respectively. Macro- and micro-damage criterion will be established sequentially. Material deformation can be controlled precisely and forming defects can be prevented effectively. This research work mainly focuses on deformation characteristics and damage generation and evolution mechanism under thermal-mechanical coupling and will provide important theoretical support for the complex shape precise forming process of Ti/Cf/TPI hybrid laminates under thermal-mechanical coupling.

Ti/Cf/TPI混杂层板作为第四代纤维金属层板中的重要一员，是空天飞机、超音速运输机等新一代运载器中重要的结构材料。目前在构件的加工成形上，变形规律还未系统掌握，还无法实现结构-性能的精确控制，易出现纤维断裂、基体开裂、界面分层等成形缺陷问题。.本项目以Ti/Cf/TPI混杂层板作为研究对象，首先，系统研究热力耦合条件下层板结构对材料变形的影响规律，探索结构与性能的对应关系；其次，从纳观-细观-宏观三个尺度来深入研究不同温度和不同加载条件对层板异质组分及界面协调变形规律的影响，提出热力耦合相关的材料本构关系及界面模型；最后，研究热力耦合条件下的损伤缺陷生成及演化机理，建立宏/微观损伤判据，从而实现材料变形精确控制，预防成形缺陷的产生。本项目着重研究热力耦合条件下Ti/Cf/TPI混杂层板的变形规律及成形缺陷生成演化机理，为复杂构件热力耦合精密成形提供重要理论支撑。

纤维金属层板在热压成形过程中是将金属、纤维增强复合材料以及相互界面间的作用相协同与集成，实现材料性能和构件形状相统一的一体化制造。在此热力耦合过程中需要对金属材料的塑性变形、纤维增强复合材料的粘弹性变形、以及相互界面的形性演变规律和机理进行深入的研究，建立材料本构方程和过程仿真模型，检验并探究在典型极限工况下的材料使用性能，分析损伤生成和演化的机制，并对材料组分和连接界面进行针对性地强化以抑制缺陷损伤生成，从而实现对材料及其构件的精准形性成形控制。项目研究的主要内容包括：（1）纤维金属层板结构热力耦合条件下的变形规律及性能演变机理；（2）纤维金属层板结构典型载荷下的力学行为及损伤生成演化机理；（3）纤维金属层板连接界面和组分多维多相性能强化设计方法。本项目获得了纤维金属层板的热力耦合变形特性及其机理，提出了纤维金属层板热力耦合下的成形方法，未来可实现纤维金属层板的形性可控精确成形；同时深度挖掘了金属、复合材料及其界面三者之间的宏微观缺陷和损伤的生成和演化机制；针对新一代的Ti/CFRP体系的纤维金属层板，提出了基于碳纳米管改性的Ti/CFRP界面强化技术和基于FeOOH接枝的Cf/Ep界面改性的界面强化技术，从两个尺度和维度大大提升了材料的力学性能；针对树脂基体的自身性能，提出了基于分子动力学仿真和机器学习相结合的全新树脂体系设计方法，成功制备了高性能环氧树脂基体和具有自修复功能的双马来酰亚胺树脂基体。基于本项目的研究基础和成果，未来新型纤维金属层板将在航空航天、舰艇船舶、海洋工程等方面具有巨大的应用前景。