航空学报 > 2026, Vol. 47 Issue (17): 233236-233236   doi: 10.7527/S1000-6893.2025.33236

基于表面应变法的DCB胶接界面断裂行为

靳易霖1, 刘雨生2, 张世杰1, 刘家成1, 姚旭丹1,3, 汪万栋1,3()   

  1. 1.西北工业大学 航空学院,西安 710072
    2.沈阳飞机设计研究所 结构部,沈阳 110087
    3.强度与结构完整性全国重点实验室,西安 710072
  • 收稿日期:2025-12-15 修回日期:2025-12-30 接受日期:2026-01-14 出版日期:2026-01-26 发布日期:2026-01-19
  • 通讯作者: 汪万栋 E-mail:w.wang@nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(12272303);国家自然科学基金(52302457)

Fracture behavior of DCB bonded interface based on surface strain method

Yilin JIN1, Yusheng LIU2, Shijie ZHANG1, Jiacheng LIU1, Xudan YAO1,3, Wandong WANG1,3()   

  1. 1.College of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China
    2.Department of Structures,Shenyang Aircraft Design & Research Institute,Shenyang 110087,China
    3.National Key Laboratory of Strength and Structural Integrity,Xi’an 710072,China
  • Received:2025-12-15 Revised:2025-12-30 Accepted:2026-01-14 Online:2026-01-26 Published:2026-01-19
  • Contact: Wandong WANG E-mail:w.wang@nwpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(12272303)

摘要:

为满足先进轻量化胶接结构的完整性需求,基于纵向应变一致准则,设计了可实现纯Ⅰ型断裂的同质(钛合金-钛合金,Ti-Ti)与异质(碳纤维增强复合材料-钛合金,Carbon Fiber Reinforced Polymer-Titanium alloy,CFRP-Ti)双悬臂梁(DCB)胶接接头,并结合分布式光纤传感(DOFS)技术与欧拉-伯努利梁理论,应用了一种基于表面应变测定来推导界面牵引-分离关系(TSR)与断裂韧性的方法,系统研究了2类接头在Ⅰ型载荷作用下的断裂行为,阐明了不同被粘物组合条件下对胶接界面的TSR、断裂韧性以及断裂过程区(FPZ)的影响机理。研究表明,该方法可有效获取断裂全过程的TSR、断裂韧性、裂纹扩展长度、内聚区尺寸等参数。将测量得到的试验数据输入有限元中进行数值仿真,可以完美复现试验过程。在纯Ⅰ型载荷下,同质与异质接头的断裂韧性分别为(0.45±0.04) N/mm和(0.49±0.08) N/mm,发现其宏观断裂韧性与内聚力本构关系受被粘物材料的影响不显著。然而,异质接头中被粘物的刚度失配显著影响FPZ的力学行为,其表现出更高的峰值牵引力((20±1) MPa)及不同的牵引力分布形态。通过提取界面上的牵引力分布,实现了对裂纹长度与断裂过程区的精确量化,为先进轻质胶接结构的失效分析与性能评估提供了重要的理论依据与数据支撑。

关键词: 牵引分离定律, DCB, Ⅰ型断裂, 被粘物, 表面应变, 分布式光纤传感

Abstract:

To meet the integrity requirements of advanced lightweight bonded structures, this study designed conventional (Titanium alloy-Titanium alloy, Ti-Ti) and bi-material (Carbon Fiber Reinforced Polymer-Titanium alloy, CFRP-Ti) Double Cantilever Beam (DCB) bonded joints capable of achieving pure Mode Ⅰ fracture based on the longitudinal strain consistency criterion, focusing on the fracture behavior of CFRP-Ti bi-material bonded joints (a key load-bearing component in lightweight structures) under Mode Ⅰ loading; meanwhile, integrating Distributed Optical Fiber Sensing (DOFS) technology with Euler-Bernoulli beam theory, a method for deriving the interface Traction-Separation Relationship (TSR) and fracture toughness based on surface strain measurements was proposed. Through systematic investigation of the fracture behavior of the two types of joints under Mode Ⅰ loading, the influence mechanisms of different adherend combinations on the interfacial TSR, fracture toughness, and Fracture Process Zone (FPZ) were clarified. Results show that the proposed method can effectively obtain key parameters throughout the fracture process, including TSR, fracture toughness, crack propagation length, and cohesive zone size, and inputting the measured test data into finite element simulations enables accurate reproduction of the test process. Under pure Mode Ⅰ loading, the fracture toughness of the conventional and bi-material joints are (0.45±0.04) N/mm and (0.49±0.08) N/mm, respectively, indicating that the macroscopic fracture toughness and cohesive constitutive relationship are mainly dominated by the adhesive layer’s own properties with no significant influence from the adherend materials; however, the stiffness mismatch of adherends in the bi-material joint significantly affects the mechanical behavior of the FPZ, which exhibits a higher peak traction ((20±1) MPa) and distinct traction distribution characteristics. By extracting the traction distribution at the interface, precise quantification of the crack length and FPZ is achieved, providing important theoretical basis and data support for the failure analysis and performance evaluation of advanced lightweight bonded structures.

Key words: traction separation relationship, double cantilever beam, Mode Ⅰ fracture, adherends, surface strain, distributed optical fiber sensing

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