2D-C/SiC复合材料热膨胀系数演化模型
Evolution model of thermal expansion coefficient for 2D-C/SiC composites
郑茹悦 1杨成鹏 1贾斐2
作者信息
- 1. 西北工业大学 力学与土木建筑学院,西安 710072
- 2. 西安电子科技大学 机电工程学院,西安 710071
- 折叠
摘要
热膨胀系数是耐高温复合材料的重要热力学参数.针对复合材料在服役条件下存在基体开裂和界面脱粘而影响其热膨胀变形的现象,通过理论模拟和实验测试,研究了含损伤 2D-C/SiC复合材料热膨胀系数随环境温度的演变行为.首先,基于Mini复合材料模型给出了组分材料的三维热失配应力计算模型;其次,引入基体开裂和界面脱粘损伤,并考虑组分材料热膨胀性能差异、纤维的横观各向同性以及泊松效应的影响,推导了Mini复合材料轴向和径向热膨胀系数的解析表达式;再次,基于[0/90]正交层压板模型和宏观应变的一致性假设,建立了 2D-C/SiC复合材料含损伤表观热膨胀系数的分析预测模型;最后,将本模型与经典Schapery模型及实验值进行对比,分析了热膨胀系数的主要影响因素.参数分析表明:基体裂纹间距、界面脱粘率、孔隙率、组分材料的弹性模量及热膨胀系数等均会影响复合材料的表观热膨胀系数,其中基体膨胀系数的影响尤为显著;验证结果表明:本模型具有合理性与正确性,其预测值与经典模型及实验曲线均吻合良好.
Abstract
Thermal expansion coefficient(TEC)is an important thermodynamic parameter of high-temperature resistant composites.The evolution behavior of the TEC of damaged 2D-C/SiC composites with ambient tempera-ture was studied by theoretical model and experimental tests for the phenomenon of matrix cracking and interface debonding,which affects the thermal expansion deformation of the material under service condition.Firstly,the three-dimensional thermal mismatch stress calculation model of constituents was given based on minicomposite model.Secondly,matrix cracking and interface debonding were introduced,and the analytical expressions for axial and radial TECs of minicomposite were derived by considering thermal expansion difference between the fibers and matrix,transverse isotropy of fibers and the Poisson's effect.Thirdly,based on the[0/90]cross-ply laminate model and the macro-strain consistency assumption,a predictive model was established towards the apparent TEC of damaged 2D-C/SiC composites.Finally,the present model was compared with the classical Schapery model and experimental data,and the main influencing factors of TEC were analyzed.Parameter analysis indicate that the ap-parent TEC of the material is affected by matrix crack spacing,interface debonding ratio,porosity,elastic modulus and TEC of the constituents,among which the influence of the matrix expansion coefficient is particularly signifi-cant.The verification results show that the proposed model is reasonable and correct,and the predicted results are in good agreement with the classical model and experimental curve.
关键词
热膨胀系数/Mini复合材料模型/2D-C/SiC/热失配应力/Schapery模型Key words
TEC/minicomposite model/2D-C/SiC/thermal mismatch stress/Schapery model引用本文复制引用
基金项目
国家自然科学基金(12072274)
陕西省自然科学基础研究计划(2021JM-123)
出版年
2024
NETL
NSTL
万方数据