权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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.

研究了复合材料层合结构的冲击后压缩问题，为评价外物冲击对复合材料层合结构压缩性能的影响提供了理论依据。问题由两部分组成：·冲击损伤的产生和发展·损伤板的压缩特性这两部分都太复杂，不能简单地解释理论上的理想解。为此，本文对两种构件进行了数值分析和模型试验，研究了冲击能量、堆积顺序等参数对构件抗压性能的影响。为了模拟界面区的损伤累积过程，提出了一种断裂单元，其模拟结果与现有理论吻合较好，并揭示了许多新的发现，如损伤累积初期的分层失稳扩展，该理论可用于分析损伤板的受压性能。在压缩问题中，进行三维有限元分析以研究屈曲性能和屈曲后行为，包括计算沿嵌入脱层沿着的断裂力学参数（能量释放率G_（12）D_2 I_（12）D_2、G_（12）D_2 II_（12）D_2、G_（12）D_2 III_（12）D_2）。该模型较好地模拟了含多个脱层的层合板的复杂压缩行为，其中必须考虑接触问题。该解很好地解释了非常复杂的实验结果，包括最终断裂前的损伤扩展。特别是，第一层离扩展发生在本分析预期的层离处。