文章信息/Info

Title:

Mesostructure Analysis of 3D Flexible Woven Preform

文章編號(hào):

1674-3962(2020)06-0458-06

作者:

劉云志; 戰(zhàn)麗; 王爭(zhēng); 張群; 李志坤

（機(jī)械科學(xué)研究總院集團(tuán)有限公司 先進(jìn)成形技術(shù)與裝備國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100083）

Author(s):

LIU Yunzhi;  ZHAN Li;  WANG Zheng;  ZHANG Qun;  LI Zhikun

（Key Laboratory of Advanced Forming Technology and Equipment, China Academy of Mechanical Sciences Group Co., Ltd., Beijing 100083, China）

關(guān)鍵詞:

柔性導(dǎo)向三維織造; 復(fù)合材料預(yù)制體; 樹脂轉(zhuǎn)移模塑成型（RTM）技術(shù); 細(xì)觀結(jié)構(gòu); 纖維截面形貌

Keywords:

3D flexible weaving technology;  composite preform;  resin transfer molding (RTM) technology;  mesostructure;  sectional morphology of fibers

分類號(hào):

TB332

DOI:

10.7502/j.issn.1674-3962.201902007

文獻(xiàn)標(biāo)志碼:

A

摘要:

針對(duì)柔性導(dǎo)向三維織造復(fù)合材料預(yù)制體的結(jié)構(gòu)表征問(wèn)題，對(duì)預(yù)制體的幾何結(jié)構(gòu)和纖維束細(xì)觀形貌進(jìn)行了研究。基于纖維截面為矩形、纖維處于伸直狀態(tài)、預(yù)制體結(jié)構(gòu)均勻一致、忽略邊緣導(dǎo)向套與纖維的纏繞區(qū)域等基本假設(shè)，建立了預(yù)制體幾何結(jié)構(gòu)模型，并通過(guò)織造實(shí)驗(yàn)驗(yàn)證了模型的合理性。通過(guò)織造層致密化壓實(shí)工藝，織造了纖維體積分?jǐn)?shù)分別為44.1%、50.0%和52.5%的預(yù)制體，采用樹脂轉(zhuǎn)移模塑成型（RTM）技術(shù)制備了復(fù)合材料試樣。將試樣研磨拋光后置于顯微鏡下觀測(cè)X/Y向纖維束沿Z向和軸向的截面細(xì)觀形貌變化特征（將纖維與平面內(nèi)X或Y向纖維之間正交鋪設(shè)的夾層區(qū)域定義為A區(qū)域，將X向纖維和Y向纖維正交疊層區(qū)域定義為B區(qū)域）。結(jié)果表明，受不同壓實(shí)載荷的影響，纖維體積分?jǐn)?shù)高的預(yù)制體，A區(qū)域的X/Y向纖維束截面形貌更趨于矩形；B區(qū)域的X/Y向纖維束，在預(yù)制體纖維體積分?jǐn)?shù)達(dá)到50%時(shí)，呈輕微的反半圓形狀，纖維體積分?jǐn)?shù)達(dá)到52��5%時(shí)，纖維束截面近似呈矩形；X/Y向纖維束沿軸向截面觀測(cè)結(jié)果顯示，在A區(qū)域和B區(qū)域的纖維束軸向截面形貌分別形成反鼓形和鼓形結(jié)構(gòu)，沿著纖維束軸向交替重復(fù)出現(xiàn)，且隨著壓實(shí)載荷的增加，制件纖維體積分?jǐn)?shù)提高，該特征更加明顯。通過(guò)分析碳纖維預(yù)制體細(xì)觀結(jié)構(gòu)特征，得出宏觀壓實(shí)致密化程度對(duì)預(yù)制體細(xì)觀結(jié)構(gòu)的影響規(guī)律，為預(yù)測(cè)復(fù)合材料性能提供了參考。

Abstract:

Targeting at the problem of structure characterization of 3D flexible woven preform, the macroscopic geometry of preform and the mesostructure of fiber bundle were studied. Based on the basic assumptions that the fiber cross section is rectangular, the fiber is straight, the structure of preform is uniform, and the winding area between edge guide sleeve and fiber is ignored, the macroscopic geometric structure model of the preform was established, and the rationality of the model was verified by the weaving experiment. Through the densification and compaction process of the woven layer, the preforms with fiber volume fractions of 44.1%, 50.0%, and 52.5% were woven, and composite material samples were prepared using resin transfer molding (RTM) technology. After grinding and polishing, the mesomorphology of X/Y fiber bundles along Z direction and axial section was observed under microscope, as the sandwich area between Z direction fiber and X direction fiber or between Z direction fiber and Y direction fiber is defined as region A, and the orthogonal stacking region between X direction fiber and Y direction fiber is defined as region B. The results show that, under the influence of different compaction loads, the cross-sectional morphology of the X/Y direction fiber bundle in the A region for the preform with high fiber volume fraction tends to be more rectangular. The cross-sectional morphology of the X/Y direction fiber bundles in the B region shows a slight reverse semicircle shape when the fiber volume fraction of the preform reaches 50%, and it is approximately rectangular when the fiber volume fraction reaches 52.5%. The axial cross-section observation results of the X/Y fiber bundles show that the axial cross-sectional morphology of the fiber bundles in the A and B regions respectively form anti-drum and drum structures, which alternately and repeatedly appear along the fiber bundle axis. With the increase of compaction load, the fiber volume fraction of the part increases, and the above characteristics are more obvious. By analyzing the mesostructure characteristics of carbon fiber preform, the influence of compaction degree on the mesostructure of the preform was obtained, which provides a reference for predicting the performance of the composite materials.