分层缺陷对复合材料层板压缩性能的影响

基于影像云纹法、表面应变测量、分级加载超声C扫描3种观测手段,对含有不同位置、尺寸、数量预制分层缺陷的复合材料层板进行了压缩试验研究,对试验中产生的子层屈曲、分层扩展、层板失稳等现象进行了细致的观察、对比与联系.结合试验结果,总结了3种不同的分层扩展模式,并基于分层扩展模式分析了子层屈曲、层板失稳等现象的产生机理.结合上述试验现象,通过比较临界失稳应力、最终破坏应力、分层纵向扩展范围等试验结果,系统地分析了分层缺陷对复合材料层板压缩性能的影响.研究结果可为复合材料结构损伤容限设计提供依据. 

Effects of delamination on compressional properties of composite laminate

Compressional behaviors of composite laminates were experimentally investigated based on three measuring methods, Shadow Moiré measurement, strain measurement on the surface of laminates and C-scan together with multi-stage loading. Laminates with artificial delamination of various depths, sizes and quantities were studied. The buckling of sub-layer, the extension of delamination and the instability phenomena during the experiments were observed, compared and connected. Three different modes of the extension of delamination were summarized based on the experimental results. The mechanisms of the buckling of sub-layer, the instability of the laminates, etc. were analyzed based on the three modes. The critical buckling stress, the final failure stress and the delamination extension extent through the vertical direction were compared and combined with the experimental phenomenon to analyze the effects of delamination on compressional properties of composite laminate systematically. The results can provide guidance for the damage tolerance designing of composite structures.