缝编织物复合板冲击分层破坏的显微镜观察研究

就缝编多层织物复合板受冲击后分层破坏进行了细致的显微镜观察分析，揭示了复合板截面各区域内所形成的裂缝纹形态，对进一步探索纤维复合材料的抗冲击分层破坏性能具有重要意义。

MICROSCOPE OBSERVATION AND ANALYSIS ON CRACKS OF STITCHING LAMINATE COMPOSITE SUBJECTED TO IMPACT

To investigate the reinforcing effectiveness and the impact resistance of the multi layer fabric composite through stitching processing, a microscope observation and analysis on delamination cracks of stitching laminate composite specimens subjectes to impact was made in this research. The different crack forms on cross section of the specimens were revealed through detailed observation on the 5 different areas along the stitching threads, including both of bobbin theread and needle theread. The observation shows that there are cracks in all the 5 areas on the cross section of the specimens. The best possible places of creating cracks are between two layers of fibers. The introduction of the bobbin thread through the thickness will prevent the formation of cracks. But due to existence of triangle resin rich areas at every entrance of the bobbin thread, more cracks are easily induced into the inner layers of the laminate from these resin rich areas, and as a result, the delamination resistance of the composite laminate is weakened through the stitching processing. This research will help us to understand the mechanism of enhancing delamination resistance of the fibre composite laminate against impact.