热塑性FRP自动铺放成型缺陷的多尺度研究进展

纤维增强型复合材料(FRP)自动铺放成型缺陷形成过程涉及多个时空尺度,仅依靠宏观失效理论及实验分析等方法无法实现对FRP铺放成型缺陷机理的研究。为了解决以上问题,本文针对热塑性FRP,分析了其铺放制造过程中常见的缺陷类型及其形成的基本原因,并结合气泡成核、热力耦合、界面增强理论及原位固结技术的国内外研究成果,指出现阶段FRP铺放缺陷机理研究方法的不足,根据现有的多尺度分析法及材料设计的嵌套式关系,提出反串行嵌套式多尺度分析方法,并讨论了基体的流动性、结晶度、黏弹性及吸湿性等微观力学参数的分析和计算方法。最后,采用灰色关联及多目标优化法,提出FRP铺放成型工艺的多尺度协同设计方法。未来研究重点是在铺放样机应用化的基础上,分析工艺参数、成型缺陷与力学性能的关联特性,揭示缺陷形成机理并优化工艺参数。

Multi-scale Research Progress of Manufacturing Defects for Thermoplastic FRP Fabricated by Automated Fiber Placement

The formation process of manufacturing defects in Fiber Reinforced Plastic (FRP) fabricated by automated fiber placement which involves different spatiotemporal scales, the mechanism of defects cannot be achieved by using macroscopic failure theory and experimental analysis methods.To solve these issues, this paper aimed at thermoplastic FRP, the common types of defects and reasons they formed were reported, and the present situation of bubble nucleation, thermo-mechanical coupling, theory of interface strengthening and in-situ consolidation were investigated.More importantly, the shortcomings of the current method for mechanism of defects were pointed out.According to existing multi-scale analysis method and nested relation of material design, multi-scale analysis method of anti-serial nested was presented, furthermore analysis and calculation method of microscopic mechanics parameters were discussed, such as fluidity of matrix, crystallinity, viscoelasticity, hygroscopicity.Finally, multi-scale collaborative design method for process parameters in FRP placement was put forward, based on methods of Grey Relational Analysis (GRA) and Multi-Objective Optimization (MOO).The future research will focus on analysis of the correlation characteristics of processing parameters, manufacturing defects and mechanical properties after application with AFP prototype.The mechanism of defects formation will be then revealed, and simultaneously, processing parameters will be optimized.