Influence of Countersink Fillet Radius on Mechanical Performance of CFRP/Al Bolted Joints

doi:10.16183/j.cnki.jsjtu.2022.288

Abstract

Abstract:

Carbon fiber reinforced polymer (CFRP) and aluminum alloys (Al) are widely used in the new generation of commercial aircraft due to their excellent mechanical/physical properties. CFRP/Al countersink bolted structures are important connection forms, where the radius of the countersink fillet affects the mechanical connection performance. The countersink fillet radius is an important factor affecting the mechanical performance of bolted joints. In this paper, the countersink fillet radius is controlled by specially-designed drill-countersink tools with different countersink fillet radii. Meanwhile, the finite element model based on the progressive damage method of composite material is established and utilized to simulate the mechanical performance of different composite/metal bolted joints. The failure mechanism of CFRP/Al bolted joints is analyzed. The results show that the countersink fillet radius can be effectively controlled by specially-designed drill-counterbore tools. The ultimate strength of bolted joints with dimple in the CFRP layer is higher than that in the aluminum alloy layer. In terms of the countersink fillet radius, both CFRP and aluminum alloy materials have the maximum strength when the countersink fillet radius is 1.0 mm. That is, the countersink fillet radius should be slightly larger than the bolt fillet radius, which is conducive to a better mechanical performance.

Key words: carbon fiber reinforced polymer (CFRP), countersink, fillet radius, mechanical joint, finite element method

CLC Number:

TH114

WANG Xianfeng, ZOU Fan, LIU Chang, AN Qinglong, CHEN Ming. Influence of Countersink Fillet Radius on Mechanical Performance of CFRP/Al Bolted Joints[J]. Journal of Shanghai Jiao Tong University, 2024, 58(3): 342-351.

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References 25

[1]	BELLINI C, COCCO V D, IACOVIELLO F, et al. Performance evaluation of CFRP/Al fibre metal laminates with different structural characteristics[J]. Composite Structures, 2019, 225: 111117. doi: 10.1016/j.compstruct.2019.111117 URL
[2]	管清宇, 夏品奇, 郑晓玲, 等. 复合材料层压板冲击后压缩强度拟合模型[J]. 上海交通大学学报, 2021, 55(11): 1459-1466. doi: 10.16183/j.cnki.jsjtu.2020.360
	GUAN Qingyu, XIA Pinqi, ZHENG Xiaoling, et al. Fitting model to compressive strength of composite laminate after impact[J]. Journal of Shanghai Jiao Tong University, 2021, 55(11): 1459-1466.
[3]	CHEN Y, LI M, YANG X, et al. Durability and mechanical behavior of CFRP/Al structural joints in accelerated cyclic corrosion environments[J]. International Journal of Adhesion and Adhesives, 2020, 102: 102695. doi: 10.1016/j.ijadhadh.2020.102695 URL
[4]	SUO H, WEI Z, ZHANG K, et al. Interfacial wear damage of CFRP/Ti-alloy single-lap bolted joint after long-term seawater aging[J]. Engineering Failure Analysis, 2022, 139: 106464. doi: 10.1016/j.engfailanal.2022.106464 URL
[5]	刘风雷, 刘丹, 刘健光. 复合材料结构用紧固件及机械连接技术[J]. 航空制造技术, 2012 (Z1): 102-104.
	LIU Fenglei, LIU Dan, LIU Jianguang. Fastener and mechanical joining technology for composite structure[J]. Aeronautical Manufacturing Technology, 2012 (Z1): 102-104.
[6]	ABSI C, ALSINANI N, LEBEL L L. Carbon fiber reinforced poly (ether ether ketone) rivets for fastening composite structures[J]. Composite Structures, 2022, 280: 114877. doi: 10.1016/j.compstruct.2021.114877 URL
[7]	QIN X, CAO X, LI H, et al. Effects of countersunk hole geometry errors on the fatigue performance of CFRP bolted joints[J]. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2022, 236(4): 337-347. doi: 10.1177/09544054211028534 URL
[8]	谢鸣九. 复合材料连接技术[M]. 上海: 上海交通大学出版社, 2016: 121-160.
	XIE Mingjiu. Joint for composites materials[M]. Shanghai: Shanghai Jiao Tong University Press, 2016: 121-160.
[9]	MERAM A, CAN A. Experimental investigation of screwed joints capabilities for the CFRP composite laminates[J]. Composites Part B: Engineering, 2019, 176: 107142. doi: 10.1016/j.compositesb.2019.107142 URL
[10]	HU J, ZHANG K, CHENG H, et al. An experimental investigation on interfacial behavior and preload response of composite bolted interference-fit joints under assembly and thermal conditions[J]. Aerospace Science and Technology, 2020, 103: 105917. doi: 10.1016/j.ast.2020.105917 URL
[11]	WANG H, ZHOU M, LIU B. Tolerance allocation with simulation-based digital twin for CFRP-metal countersunk bolt joint[C]// ASME International Mechanical Engineering Congress and Exposition. Pennsylvania, USA: American Society of Mechanical Engineers, 2018, 52019: V002T02A108.
[12]	宋广舒. 复合材料沉头螺栓连接强度分析与渐进损伤研究[D]. 郑州: 郑州大学, 2017.
	SONG Guangshu. The strength analysis and progressive damage research for countersunk composite bolted joints[D]. Zhengzhou: Zhengzhou University, 2017.
[13]	HASHIN Z. Failure criteria for unidirectional fiber composites[J]. Journal of Applied Mechanics, 1980, 47 (2): 329-334. doi: 10.1115/1.3153664 URL
[14]	DAVILA C G. Failure criteria for FRP laminates[J]. Journal of Composite Materials, 2003, 39 (4): 404-408.
[15]	PUCK A, SCHÜRMANN H. Failure analysis of FRP laminates by means of physically based phenomenological models[J]. Composites Science & Technology, 1998, 62 (12/13): 1633-1662.
[16]	HOU J P, PETRINIC N, RUIZ C. A delamination criterion for laminated composites under low-velocity impact[J]. Composites Science & Technology, 2001, 61 (14): 2069-2074.
[17]	LIU P F, LIAO B B, JIA L Y, et al. Finite element analysis of dynamic progressive failure of carbon fiber composite laminates under low velocity impact[J]. Composite Structures, 2016, 149: 408-422. doi: 10.1016/j.compstruct.2016.04.012 URL
[18]	TAN W, FALZON B G, CHIU L, et al. Predicting low velocity impact damage and compression-after-impact (CAI) behaviour of composite laminates[J]. Composites Part A: Applied Science and Manufacturing, 2015, 71: 212-226. doi: 10.1016/j.compositesa.2015.01.025 URL
[19]	CAMANHO P P, MATTHEWS F L. Stress analysis and strength prediction of mechanically fastened joints in FRP: A review[J]. Composites Part A: Applied Science & Manufacturing, 1997, 28 (6): 529-547.
[20]	LEMAITRE J, DESMORAT R. Engineering damage mechanics: Ductile, creep, fatigue and brittle failures[M]. Berlin-Heidelberg, Germany: Springer, 2005.
[21]	ASTM Committee D-30 on Composite Materials. Standard test method for tensile properties of polymer matrix composite materials: D3039/D3039M-08[S]. West Conshohocken, USA: ASTM international, 2008.
[22]	SHAN M J, ZHAO L B, LIU F R, et al. Revealing the competitive fatigue failure behavior of CFRP-aluminum two-bolt, double-lap joints[J]. Composite Structures, 2020, 244: 112166. doi: 10.1016/j.compstruct.2020.112166 URL
[23]	LI X, GAO W, LIU W. Post-buckling progressive damage of CFRP laminates with a large-sized elliptical cutout subjected to shear loading[J]. Composite Structures, 2015, 128: 313-321. doi: 10.1016/j.compstruct.2015.03.038 URL
[24]	张娇蕊, 山美娟, 黄伟, 等. 湿热环境对CFRP复合材料-铝合金螺栓连接结构静力失效的影响[J]. 复合材料学报, 2021, 38(7): 2224-2233.
	ZHANG Jiaorui, SHAN Meijuan, HUANG Wei, et al. Effects of hygrothermal environment on quasi-static failure of CFRP composite-aluminum alloy bolted joints[J]. Acta Materiae Compositae Sinica, 2021, 38(7): 2224-2233.
[25]	赵丽滨, 徐吉峰. 先进复合材料连接结构分析方法[M]. 北京: 北京航空航天大学出版社, 2015: 72-83.
	ZHAO Libin, XU Jifeng. Methods for analysis of advanced composite joining structures[M]. Beijing: Beihang University Press, 2015: 72-83.

模量参数	取值	强度参数	取值
E_x/GPa	185	X_T/MPa	3 232
E_y =E_z/GPa	9.03	X_C/MPa	1 054
G_xy=G_yz/GPa	4.27	Y_T=Z_T/MPa	70.9
G_xz/GPa	3.15	Y_C=Z_C /MPa	195.3
ν₁₂=ν₂₃=ν₁₃	0.34	S₁₂=S₁₃=S₂₃/MPa	119.1

材料	ρ/(g·cm^-3)	E/GPa	ν
Al2024(铝合金)	2.85	68	0.33
Ti6Al4V(螺栓)	4.4	115	0.3
Al7075(螺母)	2.81	71	0.33

R/mm	CFRP锪窝		铝合金锪窝
R/mm	F_e/kN	γ/%	F_e/kN	γ/%
0	18.73	—	15.95	—
0.4	20.57	9.78	17.90	12.93
0.8	21.52	4.64	18.92	5.70
1.0	21.78	1.21	22.01	3.53
1.2	21.34	-2.01	20.97	-3.18