钢/CFRP胶-编混合搭接接头渐进损伤数值模拟及损伤机制

Progressive damage numerical simulation and damage mechanism of steel/CFRP adhesive-woven hybrid lap joints

  • 摘要: 碳纤维增强聚合物复合材料(Carbon fiber reinforced polymer,CFRP)作为开采超深层石油的新型钻杆材料越来越被重视,钻杆接头用钢与CFRP管体间的搭接性能成为关键科学问题。在前期试验基础上,建立考虑内聚力损伤与三维Hashin失效准则的钢/CFRP胶-编混合搭接接头有限元模型,并通过试验验证了模型的有效性。基于该模型,系统分析了编织宽度与开孔间距对接头力学性能的影响,进一步引入有效应力与损伤扩展速率指标分析损伤机制。结果表明,编织宽度对接头性能的影响呈先增强后减弱的趋势,25 mm为最优编织宽度:随着编织宽度从10 mm增至25 mm,损伤扩展速率降低,有效应力由10.80 MPa降低到2.01 MPa第一峰值载荷和第二峰值载荷分别提升约328.14%和326.98%,失效位移相应后移0.43 mm。当编织宽度进一步增大至30 mm和35 mm时,局部应力集中效应增强,损伤扩展加快。增大开孔间距也可提高接头承载力:开孔间距从5 mm增至20 mm时,第一峰值载荷和第二峰值载荷分别提升约66.67%和32.91%,孔边应力场的相互叠加效应有所减弱,有效应力由2.08 MPa降低到1.84 MPa。揭示了胶-编混合接头的多阶段协同承载规律与内在损伤机制,为石油钻杆轻量化连接结构的设计提供了理论依据与参数指导。

     

    Abstract: Carbon fiber reinforced polymer (CFRP) has attracted increasing attention as a novel material for ultra-deep oil drilling pipes. The lap joint performance between steel connectors and CFRP tubes is a key scientific issue. Based on the previous experimental work, a finite element model of steel/CFRP adhesive-woven hybrid lap joints was established by incorporating cohesive zone damage and the three-dimensional Hashin failure criterion, and the validity of the model was verified through experiments. Based on this model, the effects of the weaving width and the hole spacing on the mechanical performance of the joints were systematically investigated. Furthermore, the effective stress and the damage propagation rate were introduced to analyze the damage mechanisms. The results show that the influence of increasing the woven width on the joint performance exhibits a trend of first enhancement and then weakening, and 25 mm is the optimal woven width. As the weaving width increases from 10 mm to 25 mm, the damage propagation rate decreases, and the effective stress decreases from 10.80 MPa to 2.01 MPa. Meanwhile, the first and second peak loads increase by approximately 328.14% and 326.98%, respectively, and the failure displacement is delayed by 0.43 mm. When the woven width is further increased to 30 mm and 35 mm, the local stress concentration effect is intensified and the damage propagation is accelerated. Increasing the hole spacing also enhances the load-bearing capacity. As the hole spacing increases from 5 mm to 20 mm, the first and second peak loads increase by approximately 66.67% and 32.91%, respectively. The superposition effect of stress fields around the holes is weakened, and the effective stress decreases from 2.08 MPa to 1.84 MPa. The multi-stage cooperative load-bearing behavior and intrinsic damage mechanisms of the adhesive-woven hybrid joints are revealed, providing theoretical guidance and parametric support for the design of lightweight connection structures in oil drilling pipes.

     

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