关键词: 复合材料, 蜂窝夹芯结构, 渐进失效分析, 内聚力模型, 挖补修理

Abstract:  For three scarf repair methods of the unilateral panel repair， the unilateral panel and core repair， the bilateral panel and core repair， the one-dimensional stepped-scarf model was used instead of the three-dimensional model to study the progressive failure mechanism of scarf repaired in honeycomb sandwich structures with plain weave panels under edgewise compressive loads. A finite element model that might simulate the damage evolution of honeycomb wall was established. And the cohesive model was used to simulate the damages of the adhesive layers. The results show that the failure modes of pristine and repaired sandwich structures are the concave buckling deformations to the non-repaired panels. The recovery rate of edgewise compression strength of repaired sandwich structures is above 75%， and the data are ranked from largest to smallest as follows：the unilateral panel repair， the bilateral panel and core repair， the unilateral panel and core repair. No damages may be seen on the panels of pristine and repaired specimens. The transverse and shear damages occur on the honeycomb wall， and the former appears first. Stress concentration occurs at the adhesive layer connected to the honeycomb core with large deformation. The longitudinal damages of the honeycomb wall only appear on the unilateral panel repair specimens， and the damages of adhesive layer appear on the bilateral panel and core repair specimens. The damages of honeycomb wall occur on the parent core materials close to the replacement core. 

Key words: composite material, honeycomb sandwich structure, progressive failure analysis, cohesive model, scarf repair