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界面对复合材料蠕变性能的影响很大。在试验分析的基础上建立了硅酸铝短纤维增强AZ91D镁基复合材料理论分析模型,利用三维有限元分析方法,系统研究了界面特性、界面上应力应变分布和短纤维位向变化对硅酸铝短纤维增强AZ91D镁基复合材料蠕变性能的影响。研究表明:界面特性,如厚度、模量,均对纤维最大轴应力和稳态蠕变速率有影响,当界面厚度增加,纤维最大轴应力减小而稳态蠕变速率增大;当界面模量增大,纤维最大轴应力增大而稳态蠕变速率减小,但当界面模量高于基体模量时,纤维最大轴应力和稳态蠕变速率均保持不变;纤维位向也影响轴应力分布和稳态蠕变速率,纤维在其末端界面上存在较大的应力和应变,此处容易产生微裂纹而使材料抗蠕变能力下降;界面对硅酸铝短纤维增强AZ91D镁基复合材料的蠕变曲线和蠕变断裂机制也有影响,其影响程度还与纤维位向有关。
The interface has a great influence on the creep properties of the composites. Based on the experimental analysis, the theoretical analysis model of aluminum silicate short fiber reinforced AZ91D magnesium matrix composites was established. The three dimensional finite element analysis method was used to systematically study the interface characteristics, the stress and strain distribution at the interface and the change of short fiber orientation. Effect of Aluminum Short Fiber Reinforced AZ91D Magnesium Matrix Composites on Creep Properties. The results show that the interfacial properties, such as thickness and modulus, all affect the maximum axial stress and steady creep rate of the fiber. When the interface thickness increases, the maximum axial stress of the fiber decreases and the steady creep rate increases. When the interfacial modulus is higher than the matrix modulus, the maximum axial stress and steady-state creep rate of fiber remain the same; the fiber orientation is also Affect the axial stress distribution and steady creep rate, the fiber in the end of the interface there is a greater stress and strain, where prone to micro-cracks and make the material creep resistance decreased; interface of aluminum short fiber reinforced AZ91D magnesium The creep curves and creep rupture mechanisms of matrix composites also have an impact, and the degree of influence is also related to the fiber orientation.