双斜接修补复合材料层合板的拉伸行为及影响因素

Tensile behavior and effect factors of double scarf-repaired composite laminates

基于试验和有限元数值方法对双斜接修补碳纤维增强聚合物(CFRP)复合材料层合板在拉伸载荷作用下的力学行为开展研究。通过试验分析了两种不同厚度的双斜接修补复合材料结构的承载能力和失效形式。结果表明,对于不同厚度的双斜接修补复合材料结构,失效强度接近,主要破坏形式均以胶层内聚破坏为主,伴随局部的90°基体开裂。利用连续介质损伤力学模型和内聚力模型分别对复合材料和胶层失效进行描述,通过数值方法开展双斜接修补结构的强度预测和损伤演化分析。数值结果与试验吻合较好,并且指出复合材料基体开裂起始早于胶层失效。通过有限元模型讨论了附加层、双斜接内部尖端所处位置和修补胶层参数对修补性能的影响。

Experimental and numerical works were performed to investigate the mechanical behavior of double scarf-repaired carbon fiber reinforced polymer(CFRP)composite laminates under tensile loading.The load capacity and damage mode of two different thicknesses double scarf-repaired composites were experimentally studied.The results indicate that for double scarf-repaired composites with different thicknesses,the failure strengths are similar and the dominated failure mode is cohesive failure of the adhesive,accompanied by partial 90° matrix crack of composites.A finite element model was established to predict the failure strength and the damage evolution,in which continuum damage model and cohesive zone model were used to describe the composite and adhesive damage respectively.The numerical results show good agreement with the test results and indicate that the matrix crack of the composites initiates prior to the adhesive failure.Based on the validated model,the influences of overlap patch,location of inner tip and adhesive properties were analyzed.