基于微结构识别的单向复合材料导热系数预估

发布时间：2018-03-17 02:20

本文选题：单向复合材料　切入点：等效导热系数　出处：《航空动力学报》2016年11期 　论文类型：期刊论文

【摘要】：以T300碳纤维/环氧树脂基单向复合材料为例,考虑纤维周围间隙缺陷的影响,建立了基于微观图像识别的等效导热系数预估方法.首先利用图像识别技术处理材料微观电镜照片,然后依据纤维体积分数稳定性判据应用几何重构技术建立了代表性单元,并通过在代表性单元(RVE)内部交界面处添加接触热阻的方法引入间隙缺陷的影响,最终利用有限元方法模拟得到等效导热系数(ETC).研究发现:间隙的位置对等效导热系数影响微弱;随着间隙缺陷占比和厚度的增加,等效导热系数显著降低;间隙缺陷占比大于0.8,无量纲间隙缺陷厚度小于0.15时,单向纤维增韧复合材料的等效导热系数受间隙影响最突出;相对于纤维和基体理想接触的情况,考虑间隙缺陷后,等效导热系数最大降幅可达52.1%.
[Abstract]:Taking T300 carbon fiber / epoxy matrix unidirectional composite as an example, the effect of gap defect around the fiber is considered. An effective thermal conductivity estimation method based on microscopic image recognition is established. Firstly, the image recognition technique is used to process the microscopic electron microscope photographs of materials, and then the representative unit is established based on the stability criterion of fiber volume fraction and geometric reconstruction technique. The effect of gap defect is introduced by adding contact thermal resistance at the interface of representative unit RVE. finally the equivalent thermal conductivity is obtained by finite element simulation. It is found that the location of the gap has little effect on the equivalent thermal conductivity. With the increase of the ratio and thickness of the gap defects, the effective thermal conductivity of the unidirectional fiber toughened composites is most affected by the gap when the ratio of the gap defects is greater than 0.8 and the thickness of the dimensionless gap defects is less than 0.15. Compared with the ideal contact between the fiber and the matrix, the maximum decrease of the equivalent thermal conductivity can reach 52.1 after considering the gap defect.
【作者单位】：南京航空航天大学能源与动力学院江苏省航空动力系统重点实验室;中国商用飞机有限责任公司上海飞机设计研究院;先进航空发动机协同创新中心;南京航空航天大学材料科学与技术学院;中国航空发动机集团有限公司中国燃气涡轮研究院;
【基金】：国家自然科学基金(11532007)
【分类号】：TB33

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