复合材料多向层板分层阻力曲线新模型研究

High performance composite materials are widely applied in modern aircrafts to achieve structural weight reduction. As one of the most common failure modes in laminated composite structures, delamination has become the bottleneck and core problem. In contrast to unidirectional laminates, multidirectional laminates are more widely used in engineering. However, the prediction on the delamination behavior is also more difficult due to complex failure mechanisms. The delamination resistance curve characterized by the delamination growth length is difficult to apply for the delamination behavior prediction and damage tolerance design of practical laminated composite structures, due to its dependence on location. Combining with further understanding on the delamination failure mechanisms, this project intends to adopt curvature radius as a new characterizing parameter for the resistance curve and establish a new delamination resistance curve. By applying advanced experimental methods, the mechanisms of the interfacial layer on the resistance curve will be revealed and a mechanical model for the resistance curve will further be developed to include the influence of the interfacial layer and the fiber bridging. Delamination growth criterion based on the mechanical model will be proposed to simulate the static delamination growth behavior in multidirectional laminates, based on the simple bi-linear cohesive zone model. The results of the project can contribute to the failure analysis and static strength prediction for composite structures with initial delamination damages, and further provide theoretical and technical supports for the damage tolerance design and analysis of composite structures in modern aircrafts.

高性能复合材料被广泛应用于现代飞行器实现结构减重。分层作为复合材料层板结构最为常见的失效形式之一，成为飞行器机体结构复合材料化的瓶颈和核心问题。与单向层板相比，多向层板在工程中应用更广泛，但失效机理复杂，其分层行为预测也更加困难。以分层扩展长度作为表征参量的阻力曲线，由于依赖于位置信息而难以用于复合材料多向层板的分层失效预测和损伤容限设计。本项目拟结合对分层失效机理的深入认识，采用曲率半径作为分层阻力曲线的表征参量，构建新型分层阻力曲线；通过先进的试验测试手段，揭示界面铺层对分层阻力曲线的影响机制，进而建立涵盖界面铺层和纤维桥接影响的分层阻力曲线力学模型；提出基于该模型的多向层板分层扩展准则，结合双线性本构内聚力模型的应用，实现多向层板静力分层扩展行为的数值模拟。研究成果有助于含分层损伤复合材料结构的失效分析和静强度预测，并为飞行器复合材料结构的损伤容限设计与分析提供理论和技术支撑。

高性能复合材料被广泛应用于现代飞行器实现结构减重。分层作为复合材料层板结构最为常见的失效形式之一，成为飞行器机体结构复合材料化的瓶颈和核心问题，深入研究分层问题并建立复合材料结构分层失效理论是保障先进复合材料结构安全性和完整性的关键。本项目结合工程实际，在对分层失效机理深入认识的基础上，揭示了界面铺层、混合比等对分层阻力曲线的影响机制，进而建立涵盖界面铺层、混合比和纤维桥接影响的分层阻力曲线力学模型；提出了基于该模型的分层扩展准则；此外建立了考虑分层阻力曲线影响的新型内聚力本构模型，发展了多向层板分层扩展行为的模拟方法，实现了多向层板静力分层扩展行为的准确预测。研究成果有助于含分层损伤复合材料结构的失效分析和静强度预测，并为飞行器复合材料结构的损伤容限设计与分析提供理论和技术支撑。相关研究成果在国际复合材料和力学领域高水平期刊上发表SCI论文26篇，在复合材料学报期刊上发表EI论文1篇，在国内核心期刊上发表论文1篇；以第1发明人授权国家发明专利1项；入选中国科协青年人才托举工程、重庆英才计划-青年拔尖人才。获评重庆市科协“自然科学优秀论文”1篇，2017-2020年《航空学报》高影响力论文1篇。结合承担单位相关专业研究生教育和学科建设，协助指导毕业硕士4名，指导在读博士生3名、硕士生5名。成功组织“中国复合材料学会第82期高端青年沙龙--先进复合材料结构失效分析与评价”，国内外学术会议做邀请报告2人次、口头报告3人次；获得重庆大学教学成果奖二等奖、十佳优秀青年教师奖。