3D-C_f/Mg复合材料的热残余应力研究

Thermal Residual Stress in 3D-C_f/Mg

采用随动硬化有限元模型,研究了三维碳纤维增强镁基复合材料(3D-Cf/Mg)基体热残余应力的大小、分布以及不同工艺处理对热残余应力的影响。同时,对复合材料进行了高、低温处理,利用XRD定性分析了处理前后复合材料基体热残余应力的变化。计算结果表明:经过-196℃低温处理后,复合材料基体的平均Mises热残余应力由169.06 MPa减小至55.29 MPa;高温处理后,基体平均热残余应力几乎不变。该结果与实验结果吻合,证明了低温处理能明显降低复合材料基体的热残余应力。

This paper proposes a nonlinear elastoplastic model and uses the finite element method to study the thermal residual stress in 3D-Cf/Mg and its modification after different treatments. Then an experimental investigation was realized by XRD, which indicates the influences of different treatments on thermal residual stress. The result shows that after a cold-treatment at -196℃, the average thermal residual stress can decrease from 169.06 MPa to 55. 29 MPa, while the thermal residual stress changes little after a heat-treatment. This calculating result agrees well with the experimental results and proves that the cold-treatment can reduce the thermal residual stress in 3D-Cf/Mg.