基于多维度建模的碳/碳软硬混编预制体孔隙分析与单胞模型  

Unit modeling and pore analysis of C/C soft-hard blended preform based on multi-dimensional modeling

作　　者：梅宝龙 董九志[1,3] 任洪庆 蒋秀明[1,3] MEI Baolong;DONG Jiuzhi;REN Hongqing;JIANG Xiuming(School of Mechanical Engineering,Tiangong University,Tianjin300387,China;China Textile Machinery Association,Beijing 100020,China;Tianjin Key Laboratory of Advanced Mechatronics Equipment Technology,Tiangong University,Tianjin300387,China)

机构地区：[1]天津工业大学机械工程学院,天津300387 [2]中国纺织机械协会,北京100020 [3]天津工业大学天津市现代化机电装备技术重点实验室,天津300387

出　　处：《纺织学报》2023年第9期108-115,共8页Journal of Textile Research

基　　金：天津市科技支撑重点计划项目(15ZSZDGX00840);天津市自然科学基金资助项目(18JCYBJC20200)。

摘　　要：为探究碳/碳软硬混编预制体在压实过程初始和最终密实2个阶段中孔隙分布及变化,解决成型后孔隙率无法预测的问题。基于碳/碳软硬混编预制体成型工艺构建一种三维四向孔隙模型,在无压缩载荷和施加压缩载荷2种工况下,从单胞模型的xoy平面和xoz平面2个维度、4个方向观测孔隙;从介观和微观2个尺度研究载荷下纤维形态与截面形状变化对单胞孔隙的影响,建立了纤维尺寸截面变化与孔隙率映射关系,提出影响孔隙率的尺寸系数,使预制体最终孔隙率具有可设计性;通过单胞孔隙模型计算得到预制体在压实阶段最小孔隙率。利用万能拉伸试验机对不同尺寸的预制体进行压实致密实验,得到不同尺寸预制体所受压缩载荷与高度变化曲线,揭示了预制体高度与孔隙率的关系并得到压实致密阶段最小孔隙率。实验结果表明最小孔隙率与理论模型误差小于3%,验证了软硬混编单胞孔隙模型表征预制体孔隙率的正确性。Objective In order to explore the pore distribution and change of the C/C soft-hard blended preform in the initial and final stages of the compaction process,the problem that the porosity can not be predicted at the completion of the preform was set and research focus.Method A 3-D four-direction pore model was established based on the C/C soft-hard weaving preform process.The pores from the xoy plane and xoz plane of the unit model in two dimensions and four directions were studied with and without compression load.The influences of fiber shape and cross section shape of the pore of the unit under the load were studied from mesoscopic and microscopic scales.The mapping relationship between the change of fiber size and porosity was solved by using the geometric model and the size coefficient affecting the porosity was proposed.Results The minimum porosity of the unit preform in the final compaction stage was found to be 26.1%by using the 3-D four-direction preform unit pore model and parameters(Tab.1).A universal tensile testing machine was used to perform compaction and densification experiments on the preforms of different sizes.Resin curing was performed on the preform under different compression loads,before the pore morphologies were observed.The results show that the compaction process of the preform consists of three stages,i.e.initial linear,nonlinear and final linear.In the initial linear stage,the height of the preform was compressed rapidly by small pressure,the load increases and the height decreases slowly in the nonlinear stage,and in the final linear stage,the load was increased while the height of the preform does not change.The porosity in the compaction process was obtained using the weighing method,and the mapping relationship between the height and porosity of the preform was obtained.The compression load and height variation curve of the three groups of preform with different bottom areas and the same height was showed,and the compression load of the three groups of experiments approximately i

关 键 词：碳/碳软硬混编预制体 多维度 单胞孔隙模型 压实致密 孔隙率 

分 类 号：TB332[一般工业技术—材料科学与工程]