Development of Functional Composites with Metallic Fiber of Expanded-ends.

扩端金属纤维功能复合材料的开发。

基本信息

批准号：
01550059
负责人：
NAKAGAWA Takao
金额：
$ 1.47万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

Strength of composites depends on strength of fibers and interface. Fibers are subjected to shear stressdue to the adhesive force of interface. Therefore, to obtain a strong composite we need to have strong interface. Interface strength is especially important in the case of short-fiber composite. But, as the matrix is polymeric materials, the strength of composites decreases with decrease of adhesive force of interface under the high-temperature environments. There are two ways to obtain interface of high strength, one is chemical adhesion and the other is anchor effect. The former depends on the temperature. On the other side, for the latter, surface of fiber is irregularly roughened, and the strength of interface increased due to the surface roughness. But the fiber strength decrease by stress concentration from the surface roughness. In the present study, to improve the strength of short-fiber composites, authors developed new composites with fiber of expanded-ends. In advance, the shape and size of fiber-ends are calculated by using two-dimensional elasto-plastic FEM. The results of calculation were that the shape was spherical-ends with the diameter five times bigger than a fiber. Practically, ends of fibers were formed into disk shape and they are inserted between the laminates of GFRP. The tensile strength of new composites increased by about 30% at the transition temperature of resin. The fatigue strength of new composites increased by about 25% on endurance limit at the same temperature, especially used Nylon-12 resin.

复合材料的强度取决于纤维和界面的强度。将纤维承受剪切应力的界面粘合力。因此，要获得强大的复合材料，我们需要具有强大的界面。在短纤维复合材料的情况下，界面强度尤为重要。但是，由于基质是聚合物材料，因此复合材料的强度随着高温环境下界面的粘合力而降低。有两种获得高强度界面的方法，一种是化学粘附，另一种是锚定效应。前者取决于温度。在另一侧，对于后者，纤维表面不规则地粗糙，并且由于表面粗糙度而增加的界面强度。但是纤维强度通过压力浓度从表面粗糙度降低。在本研究中，为了提高短纤维复合材料的强度，作者开发了新的复合材料，并具有扩展末端的纤维。事先，通过使用二维弹性塑料FEM来计算纤维末端的形状和大小。计算的结果是形状是球形末端，直径比纤维大五倍。实际上，将纤维的末端形成为圆盘形状，并将其插入GFRP的层压板之间。在树脂的过渡温度下，新复合材料的拉伸强度增加了约30％。在相同温度下，新复合材料的疲劳强度在耐力极限上增加了约25％，尤其是使用的Nylon-12树脂。