等参化FVDAM在复合材料湿热应力分析中的应用

在等参化有限元体积直接平均法（FVDAM）中引入等效湿胀系数,建立了复合材料湿热耦合的细观应力场分析模型。计算了湿热环境中不同纤维体积含量和湿含量复合材料的细观应力场。结果表明：湿热环境中复合材料界面径向应力最大值发生于纤维密集区的相邻纤维间的界面处,最小值出现在基体富区;初始吸湿对热残余应力有释放作用,最终吸湿的影响将超过热残余应力,界面应力状态也随之改变。计算所得细观应力场与有限元（FEM）法有较好的一致性。

Application of Parametric FVDAM on Hydrothermal Stress of Composite Materials

The hydrothermal coupled micromechanical model was established while equivalent coefficient of swelling was adopted in parametric finite-volume direct average method （FVDAM） in this paper. Hydrothermal stress fields of different fiber volume fraction and different moisture content were calculated by the model. The result showed that the maximal value of interfacial radial stress was appeared at the region of fiber excess while the minimum value was appeared at the region of matrix excess in hydrothermal conditions, and the initial moisture content had effects on the relaxation thermal residual stress, but at last the effect of hydro residual stress would exceed thermal residual stress, and the interracial stress state was changed at the same time. The micro-stress calculated by the method was compared with FEM, which verified its high-fidelity character.