中文摘要：

采用ABAQUS软件分析了不同纤维端部形状下碳纤维增强树脂基复合材料的纤维端部应力分布.考虑的纤维端部形状包括平面、半椭球面、楔形面.结果表明：当长径比≥0.75时,半椭球面纤维端部复合材料力学性能优于平面和楔形纤维端部复合材料.进一步研究了界面相厚度、界面相弹性模量对纤维端部轴向应力和剪应力的影响.结果表明：轴向应力σB随界面相弹性模量的增加逐渐减小,界面相弹性模量较小时（E≤4 GPa左右）,剪应力τD随着界面相弹性模量的增加而迅速增加,此后τD基本保持不变;当E≥3 GPa左右时,轴向应力σB随界面相厚度的增加逐渐减小.在所研究的界面相厚度（0.1、0.2、0.3μm）范围内,τD基本不随界面相厚度的变化而改变.所以界面相弹性模量应尽可能小于并接近于树脂基体的弹性模量（4 GPa）,并适当增加界面相厚度有利于抑制界面脱粘破坏.

英文摘要：

The stress distribution in the fiber tip region of the carbon fiber reinforced resin matrix composites was analyzed by using ABAQUS software in different fiber tip shapes.The fiber tip shapes including flat,semi-elliptical and wedge were considered.Results showed that mechanical performance of semi-elliptical fiber tip was better than that of flat and wedge fiber tips of composite materials when the ratio of length to diameter of the fiber was larger than or equal to 0.75.The influence of the interface thickness and modulus on the axial and shear stresses of the fiber tip was also studied.Results indicated that the axial stress σB decreased gradually with the increase of the interface elastic modulus.The shear stress τD increased with the increase of the interface elastic modulus rapidly when the interface elastic modulus was less than 4 GPa,and it remained nearly constant when the interface elastic modulus was greater than 4 GPa.The axial stress σB decreased gradually with the increase of the interface thickness when the interface elastic modulus was larger than or equal to 3 GPa.The interface thicknesses of 0.1,0.2 and 0.3 μm were employed,which had a little influence on the shear stress τD.As a result,the interface elastic modulus should be less than or close to the resin matrix elastic modulus （4 GPa） as far as possible.It was helpful to controlling the interface debonding failure by increasing the thickness of interface.