颗粒增强钛基复合材料力学性能数值模拟研究

发布时间：2019-04-04 14:01

【摘要】：本文以颗粒增强金属基复合材料为研究对象,利用有限元数值计算的研究方法,与细观力学和复合材料力学等相结合的的方法,对不同的金属基复合材料在拉伸载荷作用下的力学性能进行了数值模拟计算,并与实验结果进行对比,验证了此有限元分析方法的可靠性。首先,在平面问题的弹塑性理论及其有限元离散的基础上,将问题转化为非线性问题的求解,并采用切线刚度法进行求解。利用FORTRAN语言编写二维弹塑性准静态有限元程序。利用不动点迭代法,将有限元计算技术与细观力学相结合,改进前文中的二维弹塑性有限元程序,使程序实现从宏观均质模型到细观单胞模型的迭代计算过程。利用自编写的有限元程序,计算复合材料在不同温度作用下的静态拉伸力学性能,并与试验结果进行了比较,验证了该有限元程序的可靠性。其次,针对Ti C颗粒增强钛基复合材料,基于均匀化理论,建立了反映该材料微观结构特征的有限元模型。对不同TiC颗粒形状、大小以及体积百分含量对钛基复合材料的等效力学性能的影响进行了数值模拟计算。并与实验结果进行了对比,验证了本文的数值计算方法可用于TiC颗粒增强钛基复合材料力学性能的分析与研究,建立起复合材料微观结构和宏观力学行为之间的关系。最后,对程序进行推广。以SiC颗粒增强镁基复合材料为研究对象,对不同体积分数的复合材料的力学性能进行了计算。计算结果与实验结果吻合良好,说明这种与细观力学和材料学相结合的有限元计算方法,可以再一定范围内用于颗粒增强金属基复合材料的力学性能计算。
[Abstract]:In this paper, the particle reinforced metal matrix composite material is taken as the research object, and the finite element numerical calculation method is used to combine the meso-mechanics and the composite mechanics, etc. The mechanical properties of different metal matrix composites under tensile loading are numerically simulated and compared with the experimental results, and the reliability of the finite element analysis method is verified. Firstly, based on the elastic-plastic theory of plane problem and the discretization of finite element method, the problem is transformed into the solution of nonlinear problem, and the tangent stiffness method is used to solve the problem. A two-dimensional elasto-plastic quasi-static finite element program is programmed in FORTRAN language. The two-dimensional elasto-plastic finite element program is improved by combining the finite element method with the meso-mechanics by using the fixed-point iteration method, so that the iterative calculation process from macro-homogeneous model to meso-cell model can be realized by the program. The static tensile mechanical properties of composites under different temperatures are calculated by using the self-compiled finite element program. The results are compared with the experimental results and the reliability of the finite element program is verified. Secondly, based on the homogenization theory, the finite element model of Ti-C particle reinforced titanium matrix composites is established to reflect the microstructure characteristics of the composites. The effects of the shape, size and volume fraction of TiC particles on the equivalent mechanical properties of titanium matrix composites were numerically simulated. Compared with the experimental results, the numerical calculation method presented in this paper can be used to analyze and study the mechanical properties of TiC particle reinforced titanium matrix composites, and the relationship between the microstructure and macro mechanical behavior of the composites is established. Finally, the program is extended. The mechanical properties of SiC particulate reinforced magnesium matrix composites with different volume fraction were calculated. The calculated results are in good agreement with the experimental results, indicating that the finite element method combined with meso-mechanics and material science can be used to calculate the mechanical properties of particle-reinforced metal matrix composites in a certain range.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB331

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