Mechanism of Impact Damage and CAI Strength Reduction of Fiber Reinforced Composite Laminate

纤维增强复合材料层合板冲击损伤及CAI强度降低机理

基本信息

批准号：
09650116
负责人：
SUEMASU Hiroshi
金额：
$ 2.11万
依托单位：
Sophia University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

A research work is conducted to understand CAI (Compression After Impact) problem and to give a theoretical base for estimating the significance of the foreign object impact on the compressive performance of composite laminated structures. The problem consists of two parts:・ Impact damage initiation and development・ Compressive behavior of the damaged plateBoth portions are too complex to simply explain the theoretical idealized solution. So the numerical analysis and model experiments are conducted for both parts to identify the effects of the various parameters such as impact energy, stacking sequence etc on the compressive performance. In order to simulate the damage accumulation process in the interface region, a fracture element is proposed and the simulated results well coincides with the existing theory and many new findings are shown using the damage element, such as unstable delamination propagation at the early stage of the damage accumulation, propagation of all embedded delaminations instead of a few delaminations etc. The theory can be incorporated in the analysis of the compressive behavior of the damaged plate. In the compression problem, three dimensional finite element analysis is conducted to investigate the buckling performance and the postbuckling behavior including the calculation of the fracture mechanical parameter (energy release rates GィイD2IィエD2, GィイD2IIィエD2, GィイD2IIIィエD2) along the embedded delaminations. The complex compressive behavior of the delaminated laminate with many delaminations is well simulated, where the contact problem must be considered. The solution well explains the very complex experimental results including damage propagation before the final fracture. Particularly, the first delamination propagation occurred at the delamination expected from the present analysis.

进行研究工作是为了了解CAI（撞击后的压缩）问题，并为估计异物对复合层压结构的压缩性能的影响提供了理论基础。该问题由两个部分组成：・撞击损害倡议和开发・损坏的盘子部分的压缩行为太复杂了，无法简单地解释理论理想化的解决方案。因此，对两个部分进行了数值分析和模型实验，以确定各种参数的影响，例如冲击能量，堆叠序列等对压缩性能。为了模拟界面区域中的损伤加速过程，提出了断裂元件，模拟结果与现有理论充分一致，并且使用损害元素（例如，在损害加速的早期阶段传播）显示了许多新发现，例如在损害加速的早期传播，所有嵌入式分配的传播都可以进行分析。在压缩问题中，进行了三维有限元分析，以研究屈曲性能和后弯曲行为，包括沿嵌入式的隔离式的裂缝机械参数计算（能量释放速率GII D2III D2，GII D2III D2）。经过充分的模拟，在必须考虑接触问题的情况下，通过许多分层的分层层压板的复杂行为进行了良好的模拟。该解决方案很好地解释了非常复杂的实验结果，包括在最终骨折之前的损伤传播。特别是，第一个分层传播发生在当前分析预期的分层。