Nonlinear Vibration of Friction Stir Welding System of Aluminum Alloys

doi:10.3969/j.issn.1004-132X.2025.12.027

Abstract

Abstract:

Compared to traditional welding methods， friction stir welding of aluminum alloys produced joints with better quality and smaller residual stress. The study of nonlinear dynamic characteristics helped to optimize the welding processes and enhance welding quality. A nonlinear dynamics model for aluminum alloy friction stir welding systems was established by considering factors such as the flow of thermoplastic materials， time-varying forging forces， and the friction model of plastic metals. The system's differential dynamics equations were solved using the Runge-Kutta method， and the influences of tool rotation speed and feed rate on the system's nonlinear behaviors were described by employing bifurcation diagrams and phase diagrams. The results show that as the tool rotation speed increases， the system sequentially exhibits chaotic behavior and period-doubling bifurcations before stabilizing into periodic motion. As the tool feed rate increases， the system transitions from periodic motion through chaotic and period-doubling states before returning to periodic motion. Additionally， when the feed rate is within the range of 560 to 570 mm/min， the system tends to become unstable instead as the tool rotation speed increases. Proper selection of tool rotation speed and feed rate may prevent system instability and effectively reduce vibration amplitude.

Key words: aluminum alloy, friction stir welding, nonlinear dynamics, chaos and bifurcation

摘要：

铝合金搅拌摩擦焊相比传统焊接方式接头质量好、残余应力小，研究其非线性动力学特性有助于优化焊接工艺，提高焊接质量。考虑热塑性材料流动、时变顶锻力和塑性金属摩擦模型等多种因素，建立了铝合金搅拌摩擦焊系统非线性动力学模型。采用Runge-Kutta法求解系统微分动力学方程，利用分岔图、相图等描述搅拌针转速和进给速度对系统非线性行为的影响。结果表明：随着搅拌针转速增大，系统依次呈现混沌与倍周期交替后单周期振动的特性；随着搅拌针进给速度增大，系统由单周期振动经历混沌与倍周期状态后回到单周期振动。同时，当进给速度在560~570 mm / min时，随搅拌针转速增大，系统反而趋于失稳。合理选取搅拌针转速与进给速度可预防系统失稳，有效降低系统振动幅度。

关键词: 铝合金, 搅拌摩擦焊, 非线性动力学, 混沌与分岔

CLC Number:

TG453.9

Shuai MO, Yanchen ZHANG, Yaxin LI, Beibei LI, Sujiao CHEN, Nanjiang PENG, Wei ZHANG. Nonlinear Vibration of Friction Stir Welding System of Aluminum Alloys[J]. China Mechanical Engineering, 2025, 36(12): 3023-3029.

莫帅, 张燕琛, 李亚鑫, 李贝贝, 陈素姣, 彭南江, 张伟. 铝合金搅拌摩擦焊系统非线性振动特性[J]. 中国机械工程, 2025, 36(12): 3023-3029.

Figures/Tables 18

Fig.1 Structure and force diagram of friction stir welding

Fig.2 Comparison diagram of friction stir welding and metal cutting

Fig.3 Schematic diagram of material flow and bottom friction stress around the stirring needle

Fig.4 Dynamic model of friction stir welding system for aluminum alloy

Tab.1 System technical parameters

参数名称	参数值	参数名称	参数值
轴肩半径/mm	18	质量/kg	1
搅拌针半径/mm	8	压深/mm	0.1
搅拌针长度/mm	3.8	工件屈服强度/MPa	235.3

Fig.5 System displacement bifurcation diagram under the influence of excitation frequency Ω

Fig.6 Maximum Lyapunov exponent under the influence of excitation frequency Ω

Fig.7 Nonlinear response of the system at Ω =0.2328

Fig.8 Nonlinear response of the system at Ω =0.2328

Fig.9 Three-dimensional plot of the dynamic response of the system under the influence of excitation frequency Ω

Fig.10 Bifurcation diagram under the influence of excitation frequency Ω when feed rate v is varied

Fig.11 Bifurcation of system displacement under the influence of feed rate v

Fig.12 Maximum Lyapunov exponent under the influence of feed rate v

Fig.13 Nonlinear response of the system at v=0.265

Fig.14 Nonlinear response of the system at v=0.22

Fig.15 Three-dimensional diagram of the dynamic response of the system under the influence of feed rate v

Fig.16 Bifurcation diagram of the system under the influence of feed rate v when the excitation frequency Ω is varied

Fig.17 Mechanical properties of aluminum alloy friction stir welded joints under different feed speeds

References 16

[1]	MENG X， HUANG Y， CAO J， et al. Recent Progress on Control Strategies for Inherent Issues in Friction Stir Welding［J］. Progress in Materials Science， 2021， 115： 100706.
[2]	康粟，李冬晓，李晓光，等. 铝合金搅拌摩擦焊力的周期性波动特征与机制［J］. 机械工程学报， 2022， 58（12）： 55-63.
	KANG Su， LI Dongxiao， LI Xiaoguang， et al. Characteristic and Mechanism of Periodic Oscillation of Force in Friction Stir Welding of Aluminum Alloy［J］. Journal of Mechanical Engineering， 2022， 58（12）： 55-63.
[3]	BOCCARUSSO L， ASTARITA A， CARLONE P， et al. Dissimilar Friction Stir Lap Welding of AA-6082-Mg AZ31： Force Analysis and Microstructure Evolution［J］. Journal of Manufacturing Processes， 2019， 44： 376-388.
[4]	GUAN W， CUI L， LIANG H， et al. The Response of Force Characteristic to Weld-forming Process in Friction Stir Welding Assisted by Machine Learning［J］. International Journal of Mechanical Sciences， 2023， 253： 108409.
[5]	何长树，郄默繁，张志强，等. 轴向超声振动对搅拌摩擦焊过程中金属流动行为的影响［J］. 金属学报， 2021， 57（12）： 1614-1626.
	HE Changshu， Mofan QIE， ZHANG Zhiqiang， et al. Effect of Axial Ultrasonic Vibration on Metal Flow Behavior during Friction Stir Welding ［J］. Acta Metallurgica Sinica， 2021， 57（12）： 1614-1626.
[6]	LIU Q， LI W， ZHU L， et al. Temperature-dependent Friction Coefficient and Its Effect on Modeling Friction Stir Welding for Aluminum Alloys［J］. Journal of Manufacturing Processes， 2022， 84： 1054-1063.
[7]	SHI L， CHEN J， YANG C， et al. Thermal-fluid-structure Coupling Analysis of Void Defect in Friction Stir Welding［J］. International Journal of Mechanical Sciences， 2023， 241： 107969.
[8]	CHEN G， MA Q， ZHANG S， et al. Computational Fluid Dynamics Simulation of Friction Stir Welding： a Comparative Study on Different Frictional Boundary Conditions［J］. Journal of Materials Science & Technology， 2018， 34（1）： 128-134.
[9]	YANG C， DAI Q， SHI Q， et al. Flow-coupled Thermo-mechanical Analysis of Frictional Behaviors at the Tool-workpiece Interface during Friction Stir Welding［J］. Journal of Manufacturing Processes， 2022， 79： 394-404.
[10]	YAN Y， LIU G， WIERCIGROCH M， et al. Safety Estimation for a New Model of Regenerative and Frictional Cutting Dynamics［J］. International Journal of Mechanical Sciences， 2021， 201： 106468.
[11]	CHANDA A， DWIVEDY S K. Nonlinear Dynamic Analysis of Flexible Workpiece and Tool in Turning Operation with Delay and Internal Resonance［J］. Journal of Sound and Vibration， 2018， 434： 358-378.
[12]	莫帅，周长鹏，王檑，等. 机器人关节裂纹传动系统机电耦合动态特性研究［J］. 机械工程学报， 2022， 58（19）： 57-67.
	MO Shuai， ZHOU Changpeng， WANG Lei， et al. Research on Dynamic Characteristics of Electromechanical Coupling of Robot Joint Crack Transmission System［J］. Journal of Mechanical Engineering， 2022， 58（19）： 57-67.
[13]	MO S， LI Y， WANG D， et al. An Analytical Method for the Meshing Characteristics of Asymmetric Helical Gears with Tooth Modifications［J］. Mechanism and Machine Theory， 2023， 185： 105321.
[14]	MO S， LUO B， SONG W， et al. Geometry Design and Tooth Contact Analysis of Non-orthogonal Asymmetric Helical Face Gear Drives［J］. Mechanism and Machine Theory， 2022， 173： 104831.
[15]	MO S， WANG L， HU Q， et al. Coupling Failure Dynamics of Tooth Surface Morphology and Wear Based on Fractal Theory［J］. Nonlinear Dynamics， 2024， 112（1）： 175-195.
[16]	GEBHARD P. Dynamisches Verhalten von Werkzeugmaschinen bei Anwendung für das Rührreibschweißen［M］. München：Herbert Utz Verlag， 2011.