树枝状界面相开裂对纤维强度的影响

Effects of Cracking of Dendritic Interphase on the Strength of Fiber

碳纤维增强铝的复合材料在制造过程中，由于发生化学反应而在界面上形成新相。该相并非均匀附着在纤维表面，而是以纤维为主杆形成树枝状。本文利用剪切滞后理论，同时考虑到界面相亦有承受轴向外载的能力，分析了界面相开裂对纤维强度的影响。结果表明界面相与纤维间界面强度以及该界面脱粘后的摩擦应力的增加都能使纤维在给定外载下破坏的概率减小；另外界面相的厚度、沿纤维方向的弹性模量、剪切模量的增加却使上述概率增加。

The interfacial reaction product in carbon fiber reinforced aluminum is dendritic. The effect of cracking of the dendritic interphase on the strength of carbon fiber was studied using a shear lag model and taking into account the ability of the interphase to bear axial load. Analytic results show that the increase of the bond strength between the interphase and the carbon fiber, and the friction coefficient between them after debonding can decrease the broken probability of the carbon fiber under certain load. On the contrary, the increase of the thickness, the Youngs modulus along fiber direction and the shear modulus of the interphase increase the broken probability of the carbon fiber.