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发展了一种能够预测三维四向编织陶瓷基复合材料(3D-B-CMCs)拉伸模量与强度以及损伤演化过程的数值计算方法。首先,利用复合圆柱(CCA)和全局载荷分担(GLS)两种模型预测了纤维束的弹性模量和拉伸强度;然后,利用微焦点CT技术建立了能够反映3D-B-CMCs真实编织几何结构的胞元模型;其次,采用Hashin纤维束失效模型以及考虑单元尺寸的各向异性损伤力学本构模型,编制了ABAQUS/UMAT子程序,对3D-BCMCs材料宏观拉伸的整个过程进行了计算模拟,预测了宏观拉伸应力-应变曲线,并与试验结果相吻合,证明了所建立方法的合理性和UMAT程序的有效性。同时,研究和讨论了拉伸过程中材料内部不同的损伤破坏模式对复合材料整体力学性能的影响,为材料的疲劳和蠕变等力学行为的内部损伤演化提供了依据。
A numerical method was developed to predict the tensile modulus and strength of 3D-B-CMCs and the damage evolution process. First, the elastic modulus and tensile strength of fiber bundles were predicted by using CCA and GLS models. Then the micro-focus CT technique was used to establish the model that can reflect the true weave geometry of 3D-B-CMCs Structure. Secondly, the ABAQUS / UMAT subroutine was developed by using the Hashin fiber bundle failure model and the constitutive model of anisotropic damage considering the cell size. The whole process of macroscopic stretching of 3D-BCMCs was calculated Simulation and prediction of the macroscopic tensile stress-strain curve are carried out, which are consistent with the experimental results. It proves the rationality of the established method and the validity of the UMAT program. At the same time, the influence of different damage modes on the mechanical properties of composites during the drawing process was studied and discussed, which provided the basis for the internal damage evolution of the mechanical behaviors such as fatigue and creep.