Study on High Impact-resistant Stacking Sequence of CFRP Laminated Composites

CFRP层合复合材料高抗冲击堆叠顺序研究

基本信息

批准号：
01550078
负责人：
KASANO Hideaki
金额：
$ 1.28万
依托单位：
Takushoku 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 1990
项目状态：
已结题

项目摘要

The goal of the present research is to show how the impact-induced damage of CFRP of CFRP (Carbon Fiber Reinforced Plastics) is reduced by appropriately selecting the stacking sequence of unidirectional carbon fiber spreーpreg sheets. An air gun type impact testing machine is designed and manufactured to generate impact damage. This testing machine makes it possible to propel the steel balls of diameters 5mm and 10mm with maximum velocities of 160m/sec and 120m/sec, respectively. The impact damage is expected to occur between two layers with different fiber directions accompanied by delaminations. So the specimens of angle-ply laminate composites with [0^ﾟ _6/0^ﾟ _<10>/0^ﾟ _6] are employed, in which 6 kinds of ply-angle such as theta^ﾟ=15, 30, 45, 60, 75 and 90 are selected. In the impact testing, 2 kinds of steel balls mentioned above are propelled with the same velocities of 60.4m/sec. The inside of the specimens flatwise impacted are observed through a scanning acoustic microscopy, and their cross-sections are observed through a scanning electron microscopy as well. Results obtained are summarized as follows : (1) characteristic damage patterns of delaminations are seen on 0^ﾟ/theta^ﾟ and theta^ﾟ/0^ﾟ interfaces where fiber orientations are changed, and the area of the latter is considerably large compared to the former, (2) the damage areas increase with an increasing diameter steel ball or plyangl, (3) many transverse cracks are observed in the cross-sections, (4) cracks corresponding to other delaminations than those mentioned above are also seen, (5) initial compression Young's moduli before and after impact are almost the same. The conclusion is that the fiber oriectations suitably selected contribute to the reduction of the impact-induced damage and the transverse crack initiation must be prevented as well. The future work is to consider this problem from a theoretical point of view.

本研究的目的是通过适当选择单向单向碳纤维斑点表的堆叠顺序来降低CFRP（碳纤维增强塑料）的影响引起的损坏。气枪类型冲击测试机的设计和制造以产生冲击损伤。这台测试机可以使直径为5mm和10mm的钢球，最大速度分别为160m/sec和120m/sec。预计两层具有不同纤维方向的撞击损伤。因此，采用了具有[0^ﾟ _6/0^_ <10>/0^ﾟ _6]的角式层压层成分的种类，其中选择了6种类型的ply-angle，例如theta^= 15、30、30、45、45、60、75和90。在冲击测试中，上述2种钢球的速度为60.4m/sec。通过扫描声学显微镜观察了样品的内部，并通过扫描电子显微镜观察到它们的横截面。所获得的结果总结如下：（1）在0^ﾟ/theta^ﾟ和theta^ﾟ/0^ﾟ的特征损害模式中，在纤维方向变化的界面发生变化，而后者的区域被认为很大，并且与前者相比，损伤面积很大；（4）还可以看到与其他分解相对应的裂纹，（5）撞击之前和之后初始压缩的Young的模量几乎相同。结论是，适当选择的纤维取向有助于减少撞击引起的损伤，并且也必须防止横向裂纹倡议。未来的工作是从理论的角度考虑这个问题。