碳纤维复合材料论文改进型金字塔点阵结构的制备及其力学性能研究

碳纤维复合材料论文改进型金字塔点阵结构的制备及其力学性能研究 碳纤维复合材料论文:改进型金字塔点阵结构的制备及其力学性能研究 【中文摘要】近年来随着航空航天技术的飞速发展，对结构 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 提出超轻型化与多功能化的新要求。传统的夹芯结构，如蜂窝夹芯结构和泡沫夹芯结构等已经不能满足这种需要，点阵夹芯结构正是在这种背景下而产生的一种新型结构。研究 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 明点阵夹芯结构已成为当前国际上最有前景的新一代先进、轻质、超强韧、多功能结构。目前研究成果主要是通过钎焊和激光焊接方式所制备的金属点阵结构，纤维增强树脂基复合材料相对金属材料具有更高的比强度，更适合成型点阵结构，目前由于制备工艺的限制，关于复合材料点阵结构研究内容很少。本文提出了一种新型制备方法，即通过增加横杆，把面/芯接触方式由点接触变为线接触，改进了碳纤维金字塔点阵结构的预浸料二次成型工艺，进而使其面/芯间粘结强度得到提高。通过设计改进型金字塔点阵夹芯结构的制备模具，制备了两种改进型金字塔点阵夹芯结构，其芯子相对密度分别为1.48%和2.85%。通过实验和理论相结合的方法研究了该种结构在平压、剪切、侧压、和三点弯曲性能及失效机理。研究结果表明:芯子相对密度为1.48%的结构平压载荷下破坏模式是欧拉屈曲，剪切载荷下破坏模式为节点分层;相对密度为2.85%的结构平压载荷下破坏模式主要是节点破坏，剪切和弯曲载荷下破坏模式主要是节点分层，侧压载荷下破坏模式主要是剪切型宏观屈曲。可看出，本文所提出的增大面/芯粘接面积的方法，有效避免 了面/芯脱胶现象的出现，使金字塔点阵夹芯结构的整体性能得到提 高。 【英文摘要】In recent years, along with the rapid development of the aviation and aerospacetechnologies, a new type of aerospace structure with lightweight and multifunctionalitycharacteristics is needed. However, the examples for the traditional aerospace structure,sandwich structures with honeycomb or cellular foam core have been unable to meet thisneeds, a new type of sandwich structure with lattice core has been proposed. Researchshows that the lattice sandwich structure has become a new generation structure for itsowing to lighter weight, super strong and ductile, and other multifunctionality. Thepyramidal lattice structure is investigated to date have been fabricated from metal bondingusing brazing or laser welding. Carbon fiber reinforced polymer composites have an evenhigher specific strength than the light alloys and have been utilized as facesheet materials insandwich panels for demanding high strength applications. However due fabricationchallenges, CFRP composites have not been widely used for the lattice truss cores.In present paper, a new fabrication method is proposed, in which, by increasing areinforced bar at the nodes of structure, the interplay adhesive areas between the face sheetand pyramidal truss core is increased, in other words, change the‘point‘bonds intothe’ line’bonds between the face sheet and core of structure, subsequently, the adhesivebonding strength of face sheet and cores are dramatically improved. A new mould has beendesigned in order to fabricate the new pyramidal truss cores specimens. Carbon fibercomposite pyramidal truss cores with two different relative densities 1.48% and 2.85%were made. Experimental tests including out-of plane compression, shear, in-planecompression and three point bending loads have been conducted. Analytical models forpredicting the failure load associated with each mode are also presented. Results show thatdifferent failure modes of the pyramidal truss cores sandwich panels are revealed. Corefailure occurred by either (?) Euler buckling (1.48%) or (?) node fracture (2.85%) under outof plane compression. Node delamination is the dominated failure of present sandwichpanels under shear and three point bending. The core shear buckling of structures areobserved under in plane compression. The fabricated low density truss cores basing on newmethod increasing face/core bonding area have avoided effectively the face/core debondingfailure and have improved overall performance of the pyramidal lattice sandwich structure. 【关键词】碳纤维复合材料 点阵结构 制备工艺 金字塔 【英文关键词】CFRP sandwich structure pyramid lattice truss core preparation method mechanical performance failure modes 【目录】改进型金字塔点阵结构的制备及其力学性能研究 摘要 3-4 Abstract 4 第1章 绪论 7-18 1.1 国内外研究综述 7-16 1.1.1 点阵结构的制备工艺 9-12 1.1.2 点阵结构的力学性能研究 12-16 1.2 本文研究的主要内容 16-18 第2章 复合材料改进型金字塔点阵夹芯结构的制备 18-29 2.1 改进型金字塔点阵夹芯结构的胞元尺寸及芯子相对密度 18-19 2.2 改进型金字塔点阵夹芯结构的模具设计 19-23 2.3 改进型金字塔点阵夹芯结构的制备工艺流程 23-28 2.3.1 芯子制备 24-26 2.3.2 面板制备 26-27 2.3.3 胶结成型 27-28 2.3.4 制备工艺的优缺点 28 2.4 本章小结 28-29 第3章 改进型金字塔点阵结构的平压和剪切性能 29-46 3.1 引言 29 3.2 复合材料杆件和面板的基本性能 29-33 3.2.1 复合材料杆件的性能 29-31 3.2.2 复合材料面板的性能 31-33 3.3 改进型金字塔点阵夹芯结构的平压性能 33-39 3.3.1 改进型金字塔点阵夹芯结构平压理论分析 33-35 3.3.2 改进型金字塔点阵夹芯结构平压性能测试 35-39 3.4 改进型金字塔点阵夹芯结 构剪切性能 39-45 3.4.1 改进型金字塔点阵夹芯结构剪切理论分析 39-41 3.4.2 改进型金字塔点阵夹芯结构剪切性能测试 41-45 3.5 本章小结 45-46 第4章 改进型金字塔点阵结构的弯曲和侧压性能 46-56 4.1 引言 46 4.2 改进型金字塔点阵夹芯结构弯曲性能 46-50 4.2.1 改进型金字塔点阵夹芯结构三点弯曲理论分析 46-47 4.2.2 改进型金字塔点阵夹芯结构三点弯曲性能测试 47-50 4.3 改进型金字塔点阵夹芯结构侧压性能 50-55 4.3.1 改进型金字塔点阵夹芯结构侧压理论分析 50-52 4.3.2 改进型金字塔点阵夹芯结构侧压性能测试 52-55 4.4 本章小结 55-56 结论 56-58 参考文献 58-62 攻读学位期间发表的学术论文 62-64 致谢 64