Research on tensile failure mechanism of single lap bonded joint of CFRP laminates

doi:10.19936/j.cnki.2096-8000.20241028.004

Abstract

Abstract: Single lap bonded joint is a common composite material connection method, which has the advantages of high strength and excellent durability. It is widely used in engineering practice, but the failure and damage of single lap bonded joint are often encountered. In order to further study the failure mechanism of the bonded joint, single lap bonded joint samples with different lap lengths were prepared, and the load-displacement curves of the joint were obtained by tensile tests with tensioning machines and other equipment. Based on the continuous damage mechanics model and 3D Hashin failure criterion, a Cohesive unit is selected to simulate the cohesive layer damage, and the damage initiation and evolution of the bonded joint during the whole tensile phase of CFRP laminates is simulated by finite element software. The validity of the simulation results is verified by experimental data. The results show that the failure process of the joint goes from the crack formation of the adhesive layer to the damage initiation of the CFRP layer and then to the cohesive failure of the adhesive layer. Under the action of tensile load, the damage area of the joint first occurs at the end of the joint, and then gradually spreads inward. The joint is mainly subjected to shear stress and peel stress under type Ⅱ fracture mode, and shear stress is the main cause of damage initiation.

Key words: single lap joint, CFRP, injury evolution, failure mechanism, stress distribution, composites

CLC Number:

TB332

CHEN Yuliang, ZHANG Jun, WU Hewei, YANG Liu, LI Jianting. Research on tensile failure mechanism of single lap bonded joint of CFRP laminates[J]. COMPOSITES SCIENCE AND ENGINEERING, 2024, 0(10): 24-31.

References

[1] RAJAK D K, PAGAR D D, MENEZES P L, et al. Fiber-reinforced polymer composites: Manufacturing, properties, and applications[J]. Polymers, 2019, 11(10): 1667.
[2] 邹田春, 李龙辉, 刘志浩, 等. Ti-AFRP胶接接头失效过程实验和仿真分析[J]. 塑料, 2021, 50(2): 58-63.
[3] BANEA M D, SILVA L F M. Adhesively bonded joints in composite materials: an overview[J]. Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 2009, 223(1): 1-18.
[4] 顾轶卓, 李敏, 李艳霞, 等.飞行器结构用复合材料制造技术与工艺理论进展[J]. 航空学报, 2015, 36(8): 2773-2797.
[5] BUDHE S, BANEA M D, DE B S, et al. An updated review of adhesively bonded joints in composite materials[J]. International Journal of Adhesion & Adhesives, 2017, 72: 30-42.
[6] SUN L, TIE Y, HOU Y, et al. Prediction of failure behavior of adhesively bonded CFRP scarf joints using a cohesive zone model[J]. Engineering Fracture Mechanics, 2020, 228: 106897.
[7] 邹田春, 秦嘉徐, 李龙辉, 等. 钛合金-芳纶纤维复合材料单搭接接头的失效形式[J]. 高分子材料科学与工程, 2020, 36(8): 109-115.
[8] 杨本宁, 郑艳萍, 李成, 等. 复合材料胶接单搭接连接强度与失效模式研究[J]. 玻璃钢/复合材料, 2019(2): 26-32.
[9] LI R, NODA N A, TAKAKI R. Most suitable evaluation method for adhesive strength to minimize bend effect in lap joints in terms of the intensity of singular stress field[J]. International Journal of Adhesion and Adhesives, 2018, 86: 45-58.
[10] 张梦诚, 宋春生, 黄向阳, 等. 基于有限元的CFRP胶接接头损伤行为研究[J]. 数字制造科学, 2018, 16(4): 252-257.
[11] 孙中雷, 符娆. 复合材料斜接接头强度数值仿真研究[J]. 机械科学与技术, 2018, 37(10): 1611-1617.
[12] 毛振刚, 侯玉亮, 李成, 等. 搭接长度和铺层方式对CFRP复合材料层合板胶接结构连接性能和损伤行为的影响[J]. 复合材料学报, 2020, 37(1): 121-131.
[13] 朱兆一, 李晓文, 李妍, 等. 基于内聚力模型的CFRP层合板胶接结构力学行为研究[J]. 玻璃钢/复合材料, 2019(8): 5-10.
[14] 邹田春, 巨乐章, 李龙辉, 等. 铺层方式对CFRP-Al单搭接接头胶接性能的影响[J]. 材料研究学报, 2022, 36(9): 715-720.
[15] 胡春幸, 侯玉亮, 铁瑛, 等. 不同胶接参数对CFRP层合板单搭胶接结构强度的影响及优化设计[J]. 机械工程学报, 2021, 57(8): 154-165.
[16] 王念. 复合材料层合板冲击损伤及损伤容限研究[D]. 南京: 南京航空航天大学, 2014.
[17] MATZENMILLER A, LUBLINER J, TAYLOR R L. A constitutive model for anisotropic damage in fiber-composites[J]. Mechanics of Materials, 1995, 20(2): 125-152.
[18] HOU Y, TIE Y, Ll C, et al. Low-velocity impact behaviors of repaired CFRP laminates: Effect of impact location and external patch configurations[J]. Composites Part B: Engineering, 2019, 163: 669-680.
[19] DUGDALE D S. Yielding of steel sheets containing slits[J]. Journal of the Mechanics and Physics of Solids, 1960, 8(2): 100-104.
[20] BARENBLATT G I. Equilibrium cracks formed during brittle fracture rectilinear cracks in plane plates[J]. Journal of Applied Mathematics and Mechanics, 1959, 23(4): 1009-1029.
[21] BENZEGGAGH M L, KENANE M. Measurement of mixed-mode delamination fracture toughness of unidirectional glass/epoxy composites with mixed-mode bending apparatus[J]. Composites Science and Technology, 1996, 56(4): 439-449.
[22] KENANE M, BENZEGGAGH M L. Mixed-mode delamination fracture toughness of unidirectional glass/epoxy composites under fatigue loading[J]. Composites Science and Technology, 1997, 57(5): 597-605.