含纤维断裂复合材料热阻变化的细观建模

发布时间：2018-07-05 03:29

本文选题：纤维增强 + 损伤检测　；参考：《复合材料学报》2017年01期

【摘要】：为探讨单向纤维增强复合材料中纤维损伤与材料热阻变化之间的关系,建立了由纤维断裂引起热阻变化的细观理论模型,并利用该模型对热阻变化率进行了定性分析。针对纵向传热与垂直传热两种情形下的热阻进行分析,结合Weibull纤维强度分布模型,引入纤维失效长度作为纤维链段的最小长度,获得了纤维断裂引起的复合材料纵向和沿厚度方向热阻变化率的解析函数。采用Monte-Carlo随机方法对外加应力作用下复合材料热阻随着纤维断裂而发生变化的过程进行模拟。研究结果表明:无论是纵向热阻还是厚度方向的热阻,热阻变化率均随纤维断点数目的增大而线性递增;纤维体积组分越大,热阻变化率越大。纵向热阻变化率随着纤维/基体导热系数比β的增大而迅速增大,但当β10时增大的幅度逐渐减弱;而厚度方向的热阻变化率则随着β的增大先急剧增大而后递减,当纤维与基体的导热系数相当时(在β=1附近)达到最大值。
[Abstract]:In order to study the relationship between fiber damage and thermal resistance change in unidirectional fiber reinforced composites, a meso-theoretical model of thermal resistance change caused by fiber fracture was established, and the change rate of thermal resistance was qualitatively analyzed by using the model. The thermal resistance of longitudinal heat transfer and vertical heat transfer is analyzed. According to Weibull fiber strength distribution model, fiber failure length is introduced as the minimum length of fiber chain segment. The analytical function of the variation rate of the longitudinal and thickness thermal resistance of the composites caused by fiber fracture is obtained. Monte-Carlo stochastic method is used to simulate the process of the thermal resistance of composite material changing with the fracture of fiber under the action of applied stress. The results show that both longitudinal thermal resistance and thickness direction thermal resistance increase linearly with the increase of fiber breakpoints, and the larger the fiber volume component, the greater the change rate of thermal resistance. The change rate of longitudinal thermal resistance increases rapidly with the increase of fiber / matrix thermal conductivity ratio 尾, but decreases gradually when 尾 10:00 increases, while the change rate of thermal resistance in thickness direction increases sharply first and then decreases with the increase of 尾. When the thermal conductivity of fiber and matrix is equal (near 尾 ~ (1), the maximum value is obtained.
【作者单位】：暨南大学理工学院重大灾害与控制教育部重点实验室;
【基金】：国家青年科学基金(11302083) 国家自然科学基金重点项目(11032005)
【分类号】：TB332

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