基于X射线原位拉伸的三维针刺预制体增强纳米孔酚醛复合材料的微观损伤演化  

Micro-fracture behaviors of 3D needle punching fabric reinforced nanoporous phenolic composites based on in-situ X-ray

作　　者：钱震 曹宇 周耀忠 蔡宏祥 赵欣 王鹏 侯敏 陈炳斌 牛波 张亚运 龙东辉[1] QIAN Zhen;CAO Yu;ZHOU Yaozhong;CAI Hongxiang;ZHAO Xin;WANG Peng;HOU Min;CHEN Bingbin;NIU Bo;ZHANG Yayun;LONG Donghui(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;Beijing Xinhang Mechanics&Electricity Equipment CO.,LTD.,Beijing 100074,China)

机构地区：[1]华东理工大学化工学院,上海200237 [2]北京星航机电装备有限公司,北京100074

出　　处：《复合材料学报》2023年第8期4460-4470,共11页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(22078100,52102098);中国博士后科学基金(2022 M711140)。

摘　　要：纤维布/网胎交替叠层针刺是一种低成本、易成型的立体织物制造技术,但是针刺的随机性会给材料的损伤演化、力学分析和性能预测带来极大的挑战。本文以纤维布/网胎交替叠层针刺增强的纳米孔树脂基防隔热复合材料为例,采用原位拉伸X射线Micro-CT技术,揭示了复合材料在轴向拉伸载荷下的损伤演化过程。并采用纤维中心线自动跟踪算法对采集的三维图形数据化处理,量化分析了纤维在拉伸过程中的角度偏转。最后基于Micro-CT重构的三维结构,建立了高精度的有限元分析模型,并进行了轴向拉伸行为分析。结果表明:复合材料中的损伤始于材料的最外层,其中网胎层中的微裂纹主要产生于针刺位点处的局部富树脂区域,而纤维布层中的微裂纹主要源于纤维束中紧密排布的纤维之间;纤维布可以通过阻隔裂纹向材料内部继续扩展的方式,提升材料的韧性;在轴向拉伸载荷下,材料中的纤维会一致地向外部发生偏转,表现出负泊松比的性质,避免了断口处的“颈缩”现象;有限元分析与实验结果吻合良好。本文的研究方法和结果可为三维复杂结构材料的微观断裂分析、性能预测与结构优化提供参考。Alternately stacking needling technology is a straight forward way to prepare three-dimensional(3D)fabrics,but randomly needling process will bring great challenges to the damage evolution,mechanical analysis and property prediction.In this paper,the damage evolution of nanoporous phenolic composites reinforced by alternately stacking fiber felt and woven fabric was revealed by in-situ X-ray Micro-CT device.And the angle deflections of fiber were described quantitatively under the loading of axial tensile by automatic tracing of microtubule centerlines.Finally,based on the 3D reconstructed structure,a high-precision finite element analysis model was established,and the axial tension mechanical behavior analysis was carried out.The results show that the damage in composite starts from the outmost layer where the microcracks in the fiber felt mainly originate from the resinrich zone in the needling area,while the microcracks in the woven fabric are among filaments in fiber bundle.Besides,the woven fabric can improve the toughness of composite by preventing the microcrack expanding into the inner.The fibers in composite will consistently deflect to the outside,showing the property of negative Poisson's ratio,avoiding the "neck contraction" phenomenon at the fracture.The finite element analysis agrees with the results of experiments.The methods and results in this paper can provide a precious reference for microscopic fracture analysis,property prediction and structural optimization of complex 3D composite.

关 键 词：原位Micro-CT技术 损伤演化 针刺纤维预制体 有限元分析 纳米孔树脂 

分 类 号：TB332[一般工业技术—材料科学与工程]