铺放工艺对碳纤维复合材料拉、弯力学行为影响研究

发布时间：2019-05-13 09:22

【摘要】：作为新型的复合材料结构件制造技术,自动铺放具有高生产质量、高生产效率以及低人工成本等优势。目前,对于碳纤维复合材料铺放工艺的研究工作主要集中于两方面,一方面是对于复合材料铺放轨迹研究,另一方面则是复合材料自动铺放工艺参数优化研究。因此,本文主要从这两大主要研究方向入手,探究了主应力铺放轨迹对开孔层合板力学性能的影响以及铺放工艺参数对层合板层间性能的影响,并进行了相关的数值模拟和试验验证,同时,为进一步探索碳纤维复合材料的铺放工艺奠定了基础。首先简要论述了树脂基复合材料以及复合材料自动铺放技术,重点介绍了变刚度复合材料设计方法、复合材料铺放工艺参数优化、复合材料开孔板渐进损伤失效分析及其国内外研究现状。结合最大主应力铺放轨迹设计方法和自动铺放工艺参数优化,提出了课题的研究背景与意义。最后,给出了本文的研究内容和结构框架。其次论述了复合材料力学相关基础理论,对于单一角度铺层的应力应变关系进行了简要概述,并基于单一角度铺层应力应变关系推导得出了变角度纤维层合板应力应变关系。最后简要介绍了几种常见的内聚力模型的本构关系,为后续变刚度层合板的设计及损伤失效分析,短梁剪切层间性能分析奠定基础。针对复合材料开孔板铺放轨迹进行了研究,利用B样条曲线插值拟合获取了开孔板最大主应力铺放轨迹并通过离散网格法建立了变刚度开孔板模型,通过引入Tsai-Wu损伤失效判据以及常刚度退化准则,进行了拉伸失效数值模拟及损伤失效分析,并分别铺放了两组常刚度、变刚度开孔板试验样件,进行了拉伸对比试验。采用试验与数值模拟相结合的手段,探索不同铺放压力与复合材料层间性能之间的关系。建立包含内聚力单元的短梁剪切有限元模型,利用Linde提出的损伤失效判据,研究不同压力条件下短梁剪切试验的损伤演化过程及机理,同时,利用热压罐、铺放平台、万能试验机等试验设备进行了短梁剪切试验,并与仿真结果进行了对比分析。最后对本文的研究内容作了总结,对需进一步研究的内容进行了展望。
[Abstract]:As a new manufacturing technology of composite structure parts, automatic laying has the advantages of high production quality, high production efficiency and low labor cost. At present, the research work on the laying process of carbon fiber composites mainly focuses on two aspects: on the one hand, the research on the placement track of the composites, on the other hand, the optimization of the process parameters of the automatic placement of carbon fiber composites. Therefore, starting from these two main research directions, this paper mainly explores the influence of principal stress laying track on the mechanical properties of porous laminated plates and the influence of paving process parameters on the interlaminar properties of laminated plates. The related numerical simulation and experimental verification are carried out, and the foundation is laid for further exploration of the laying process of carbon fiber composites. Firstly, the resin matrix composites and the automatic placement technology of composite materials are briefly discussed, with emphasis on the design method of variable stiffness composites and the optimization of composite laying process parameters. Progressive damage failure analysis of composite porous plates and its research status at home and abroad. Combined with the design method of maximum principal stress paving trajectory and the optimization of automatic laying process parameters, the research background and significance of the subject are put forward. Finally, the research content and structure framework of this paper are given. Secondly, the basic theory of composite mechanics is discussed, the stress-strain relationship of single angle lamination is briefly summarized, and the stress-strain relationship of fiber laminated plate with variable angle is derived based on the stress-strain relationship of single angle lamination. Finally, the constitutive relations of several common cohesion models are briefly introduced, which lays a foundation for the subsequent design, damage and failure analysis of laminated plates with variable stiffness and the analysis of shear interlaminar properties of short beams. In this paper, the paving trajectory of composite orifice plate is studied, and the maximum principal stress paving trajectory of open hole plate is obtained by B-spline curve interpolation fitting, and the model of variable stiffness orifice plate is established by discrete grid method. By introducing Tsai-Wu damage failure criterion and constant stiffness degradation criterion, the numerical simulation of tensile failure and damage failure analysis are carried out, and two groups of constant stiffness and variable stiffness orifice plate test samples are laid out respectively, and the tensile contrast test is carried out. The relationship between different laying pressure and interlaminar properties of composites was explored by means of experiment and numerical simulation. The finite element model of short beam shear including cohesion element is established. The damage evolution process and mechanism of short beam shear test under different pressure conditions are studied by using the damage failure criterion proposed by Linde. At the same time, the hot pressure tank is used to lay the platform. The short beam shear test was carried out by universal testing machine and other test equipment, and the results were compared with the simulation results. Finally, the research contents of this paper are summarized, and the contents that need to be further studied are prospected.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TQ342.742

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