纳米碳管增强陶瓷基复合材料热残余应力分析

Analysis of thermal residual stresses for ceramic composite reinforced with carbon nano-tube

针对纳米碳管与陶瓷材料热膨胀系数的差异导致的热失配问题,采用复合材料细观力学方法,利用有限元分析软件ANSYS建立了不同长径比的纳米碳管增强陶瓷基复合材料模型,模拟降温冷却过程中纳米碳管的性质对纳米碳管增强陶瓷基复合材料热残余应力变化特征的影响;利用轴对称体弹性力学理论导出纳米碳管贯穿陶瓷基体时纳米碳管增强复合材料的热残余应力解析式,所得结果与数值模拟结果一致,证明数值模拟方法的可靠性.研究表明:纳米碳管的弹性模量、热膨胀系数、体积分数、长径比和温度差等因素的变化对复合材料热残余应力有不同程度的影响.

In order to solve the problem of thermal mismatch between nano-tube and ceramic matrix, a model with different aspect ratios is established to simulate the influence of nano-tube＇s properties on the residual stress of ceramic composites reinforced with carbon nano-tube for decreasing temperature by the meso-scopic mechanical method. The analyzed equation to calculate the residual stress is derived by utilizing the ax-symmetric elastic mechanical theory for ceramic composites with continuous carbon nano-tube, and the results are consistent with those from finite element method, which verify the reliability of the numerical simulation. The results show that the elastic modulus, thermal expansion coefficient, volume fractions, aspect rations and temperature differences for carbon nano-tubes have influences in varying degrees on the residual stress of ceramic composites reinforced with carbon nano-tube.