圆台大端纤维的拔出力分析

贝壳珍珠母中的文石片具有中间薄两端厚的特殊形貌，受此启发，把复合材料中的纤维设计成两端部为圆台状的大端异型体，可使复合材料的强韧性得以改善。本文考虑均匀分布和含量相同的圆台大端纤维和平直纤维增强复合材料，利用剪滞理论分别计算了2种纤维的与材料强韧性密切相关的拔出力。计算结果表明:圆台大端纤维的最大拔出力明显大于平直纤维的最大拔出力；基体和纤维的材料常数以及几何尺寸对最大拔出力有较大影响；在不改变基体和纤维物性时，只要合理选取形体优化设计的圆台大端纤维以及适当增加界面摩擦系数，也可使复合材料的强韧性增大。

The Pullout Force Analysis of Fiber with Shape of Frustum-Cone-Tapered

Inspired by aragonite platelet of thick ends in shell nacre, the ends of fibers were designed with the shape of frustum- cone tapered to improve fiber strength and toughness. Frustum of cone fiber and straight fiber were considered. They are reinforced composite with uniform arrangement. At the same time the maximum pullout forces of the two fibers were calculated through shear lag theory. The results show that the maximum pullout force of the presented fiber is greater than that of straight fiber and is related to geometrical and material parameters. The toughening can be enhanced when the composite constituted optimum shaped fiber and the frictional coefficient of interface are improved under the condition of unchanged physical properties of matrix and fiber.