1、碳纖維復合材料論文：改進型金字塔點陣結構的制備及其力學性能研究【中文摘要】近年來隨著航空航天技術的飛速發(fā)展，對結構設計提出超輕型化與多功能化的新要求。傳統的夾芯結構，如蜂窩夾芯結構和泡沫夾芯結構等已經不能滿足這種需要，點陣夾芯結構正是在這種背景下而產生的一種新型結構。研究表明點陣夾芯結構已成為當前國際上最有前景的新一代先進、輕質、超強韌、多功能結構。目前研究成果主要是通過釬焊和激光焊接方式所制備的金屬點陣結構，纖維增強樹脂基復合材料相對金屬材料具有更高的比強度，更適合成型點陣結構，目前由于制備工藝的限制，關于復合材料點陣結構研究內容很少。本文提出了一種新型制備方法，即通過增加橫桿，把面/芯接觸

2、方式由點接觸變?yōu)榫€接觸，改進了碳纖維金字塔點陣結構的預浸料二次成型工藝，進而使其面/芯間粘結強度得到提高。通過設計改進型金字塔點陣夾芯結構的制備模具，制備了兩種改進型金字塔點陣夾芯結構，其芯子相對密度分別為1.48%和2.85%。通過實驗和理論相結合的方法研究了該種結構在平壓、剪切、側壓、和三點彎曲性能及失效機理。研究結果表明：芯子相對密度為1.48%的結構平壓載荷下破壞模式是歐拉屈曲，剪切載荷下破壞模式為節(jié)點分層；相對密度為2.85%的結構平壓載荷下破壞模式主要是節(jié)點破壞，剪切和彎曲載荷下破壞模式主要是節(jié)點分層，側壓載荷下破壞模式主要是剪切型宏觀屈曲。可看出，本文所提出的增大面/芯粘接面積的

3、方法，有效避免了面/芯脫膠現象的出現，使金字塔點陣夾芯結構的整體性能得到提高。【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,

4、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

5、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 faceshe

6、et 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,

7、 the interplay adhesive areas between the face sheetand pyramidal truss core is increased, in other words, change thepointbonds intothelinebonds between the face sheet and core of structure, subsequently, the adhesivebonding strength of face sheet and cores are dramatically improved. A new mould has

8、 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 hav

9、e 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%) un

10、der 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

11、 area have avoided effectively the face/core debondingfailure and have improved overall performance of the pyramidal lattice sandwich structure.【關鍵詞】碳纖維復合材料 點陣結構 制備工藝 金字塔【英文關鍵詞】CFRP sandwich structure pyramid lattice truss core preparation method mechanical performance failure modes【目錄】改進型金字塔點陣結構的制備

12、及其力學性能研究 摘要 3-4 Abstract 4 第1章 緒論 7-18 1.1 國內外研究綜述 7-16 1.1.1 點陣結構的制備工藝 9-12 1.1.2 點陣結構的力學性能研究 12-16 1.2 本文研究的主要內容 16-18 第2章 復合材料改進型金字塔點陣夾芯結構的制備 18-29 2.1 改進型金字塔點陣夾芯結構的胞元尺寸及芯子相對密度 18-19 2.2 改進型金字塔點陣夾芯結構的模具設計 19-23 2.3 改進型金字塔點陣夾芯結構的制備工藝流程 23-28 2.3.1 芯子制備 24-26 2.3.2 面板制備 26-27 2.3.3 膠結成型 27-28 2.3.4

13、 制備工藝的優(yōu)缺點 28 2.4 本章小結 28-29 第3章 改進型金字塔點陣結構的平壓和剪切性能 29-46 3.1 引言 29 3.2 復合材料桿件和面板的基本性能 29-33 3.2.1 復合材料桿件的性能 29-31 3.2.2 復合材料面板的性能 31-33 3.3 改進型金字塔點陣夾芯結構的平壓性能 33-39 3.3.1 改進型金字塔點陣夾芯結構平壓理論分析 33-35 3.3.2 改進型金字塔點陣夾芯結構平壓性能測試 35-39 3.4 改進型金字塔點陣夾芯結構剪切性能 39-45 3.4.1 改進型金字塔點陣夾芯結構剪切理論分析 39-41 3.4.2 改進型金字塔點陣夾芯結構剪切性能測試 41-45 3.5 本章小結 45-46 第4章 改進型金字塔點陣結構的彎曲和側壓性能 46-56 4.1 引言 46 4.2 改進型金字塔點陣夾芯結構彎曲性能 46-50 4.2.1