扩展有限元方法与内聚力模型耦合下斜接修补复合材料的胶层损伤和缺陷

将扩展有限元方法（XFEM）与内聚力模型（CZM）耦合用于斜接修补复合材料的胶层分析，实现了对复合材料与修补胶层之间的脱粘以及胶层内部裂纹扩展现象的描述，模拟得到的结构强度与试验结果吻合较好。对复合材料与胶层的界面缺陷和胶层内部缺陷展开分析，讨论了缺陷长度和缺陷位置对结构强度的影响。结果表明：在相同条件下，结构具有界面缺陷比具有胶层内部缺陷更加危险；结构强度受缺陷长度和与缺陷尖端相邻复合材料铺层角度的共同影响，随着缺陷长度的增加而降低，降低速率大于缺陷长度增长比例；当缺陷位置不同时，结构强度主要与缺陷对应位置的平均剪应力水平相关。最后，通过参数分析讨论了界面剪切强度的影响。

Adhesive damage and defect analysis of scarf-repaired composite by combining extended finite element method and cohesive zone model

The extended finite element method(XFEM) and cohesive zone model(CZM) were combined to investigate the adhesive layer of scarf-repaired laminates, which could describe the debonding between composite and adhesive layer and the crack propagation in the adhesive at the same time. The numerical strength shows good agreement with test results. Both the interface defect and inner defect were taken into consideration, the influences of defect length and defect location were analyzed. The results indicate that the structure with inner defect is more dangerous than that with interface defect under the same condition. The structure strength which is influenced by both the defect length and the ply orientation near the defect tip decreases with the increased defect length. And the decrease rate is larger than the increase rate of defect length. When the defect location changes, the structure strength is mainly associated with the average shear stress level of adhesive layer at corresponding region. At last, parameter study was performed to investigate the influence of the interface shear strength.