钛基复合材料压气机叶环应力的数值模拟

Numerical Simulation on Stress Distribution of Ti-Matrix Composite Ring

采用有限元分析方法,建立三维循环对称模型,对连续Si C纤维增强钛基复合材料压气机叶环的应力进行了研究。考虑周围基体包套和中心复合材料的热残余应力,重点分析了叶环尺寸、温度及基体材料性能对叶环应力分布的影响。结果表明,当叶环直径较小、工作温度较低时,叶环的最大环向应力点在内径;随着直径增大、工作温度升高,最大环向应力点出现在中心复合材料靠近内径一侧。基体材料的弹性模量、热膨胀系数和密度,对叶环的应力分布有重要影响,应尽量选择密度低、弹性模量和热膨胀系数较大的钛合金作为基体材料。

A three-dimensional cyclic symmetry finite element model was developed to investigate the stress distribution of compressor ring which was fabricated by continuous SiC fiber reinforced titanium-ma？trix composites （TMC）. The effects of size of the ring, temperature and properties of the matrix material on the stress distribution were analyzed emphatically when taking thermal residual stresses between matrix cladding and composite core into consideration. The results indicate that when the diameter of TMC ring is smaller and working temperature is lower, the hoop stresses have a maximum value at the inner diameter （ID） of the ring; as the diameter of the ring and working temperature increase, the hoop stresses reach a peak value at the ID of composite core. The elastic modulus, coefficients of thermal expansions （CTEs） and density of matrix material have a significant effect on the stress distribution of TMC ring. Low density, rela-tively high elastic modulus and CTEs titanium alloy should be selected as the preferable matrix material.