摘要
采用ANSYS有限元分析软件,对 SCS－6 SiC/Ti－24Al-11Nb复合材料的残余热应力进行数值模拟,重点分析了纤维排布对残余热应力的影响。结果表明,在高温和热等静压成型的工艺条件下,与四方纤维排布模型相比,六方纤维排布模型的残余热应力较小,应力分布也较均匀,不易导致基体开裂。研究结果为SiC纤维增强 Ti基复合材料的制备方法和工艺提供了一定的依据。
The residual thermal stress which greatly affects all properties of composites is inevitable due to the mismatch of the thermal expansion coefficients (TEC) between fiber and matrix. It was analyzed by using finite element simulation in SCS-6 SiC/Ti-24Al-11Nb composite. Three models of fiber array in the composite were considered and the temperature-dependent material properties were used. The compression stress was found in the radial direction and the tensile stress in the tangential direction in the three models. However, in single fiber model, the residual stress is more homogenous and smaller compared with the square fiber geometry and the hexagonal fiber geometry. It is pointed out that in a real composite system hexagonal fiber geometry is superior because the distribution and the magnitude of the residual stress are similar to those in the single fiber model. In the square fiber geometry, it is easy to make the matrix crack due to the larger residual tangential stress, especially at the position with a smaller fiber distance.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2002年第2期184-187,共4页
Journal of Northwestern Polytechnical University
基金
航空科学基金(98CB0401)
