复合材料单搭接胶接接头低速冲击数值模拟

摘要

数值模拟研究了不同胶胶接的HTS40/977-2碳纤维层合板单搭接胶接接头低速冲击性能.对HTS40/977-2层合板冲击过程进行仿真,与实验对比验证了HTS40/977-2层合板材料参数的有效性.采用基于Hashin准则的本构关系模拟层合板面内损伤,采用内聚力单元模拟层合板的层间分离和胶层的失效,分别建立了Araldite AV138、Araldite 2015和Sikaforce 7752三种不同胶胶接接头低速冲击有限元模型,研究了胶接接头在3 J和4 J能量冲击下的失效模式和能量吸收.在失效模式方面,发现Araldite AV138、Araldite 2015 和Sikaforce 7752三种胶接接头胶层的失效模式分别为胶层完全失效、胶层部分失效和胶层未失效,三种胶接接头都出现了不同程度的层合板层间损伤,并且层间损伤依次减小.在能量吸收方面,3J能量冲击下Araldite AV138、Araldite 2015和Sikaforce 7752吸收能量分别为2.73 J、2.06 J、1.67 J,4 J能量冲击下吸收能量分别为2.91 J、2.49 J、2.26 J.仿真结果表明,在低速冲击载荷下胶接接头的失效模式和能量吸收与胶的属性密切相关.胶的韧度越低,接头损伤越严重,能量吸收越多;胶的韧度越高,接头抵抗损伤的能力越强.研究可为复合材料胶接设计与分析提供参考.%The low speed impact performances of HTS40 /977-2 carbon fiber laminates single lap adhesively bonded joints were studied with numerical simulation using different adhesives. Firstly,the impact process of HTS40 /999-2 laminates was simulated,and the effectiveness of material parameters of HTS40 /977-2 laminates was verified compared with the test results. Then the constitutive model based on Hashin criterion was used to simulate the inner damage of the laminates and the cohesive element was used to simulate separation of inter-laminate and failure of adhesive layer. The finite element models for adhesively bonded joints with different adhesives including Araldite AV138,Araldite 2015 and Sikaforce 7752 were established to study their adhesive layers'failure mode and energy absorption under impacts of 3 J and 4 J energy. It was shown that the failure modes of adhesively bonded joints of Araldite AV138,Araldite 2015 and Sikaforce 7752 are complete,partial and zero debonding between adhesive layers,respectively; different degrees of interlaminate damage are observed for these 3 joints and their damage degrees decrease in turn; the energy absorptions for joints of Araldite AV138,Araldite 2015 and Sikaforce 7752 under 3 J energy shock are 2. 73 J,2. 06 J and 1. 67 J, respectively; their energy absorptions under 4 J energy shock are 2. 91 J,2. 49 J and 2. 26 J,respectively. The simulation results indicated that the failure modes and energy absorptions of adhesively bonded joints are closely related to properties of adhesives under low-velocity impact; the lower the toughness of adhesive,the more serious the joints'damage and the more the energy absorption; the higher the toughness of adhesive,the stronger the joints'anti-damage ability; the study can provide a reference for design and analysis of composite material adhesive bonding.