Influence of Welding Sequence on Residual Stress and Distortion in Rectangular Welding of 6061 Aluminum Alloy

2013 ◽  
Vol 668 ◽  
pp. 890-897
Author(s):  
Yi Jie ◽  
Li Can ◽  
Zhong Gang Sun

This paper presented a detailed finite element simulation on the basis of elastic-plastic method combined with thermo-mechannical coupling algorithm,and the software abaqus was used for the welding simulation of thin-walled 6061-T6 aluminum. The residual stress and distortion with various types of welding sequence were investigated and the optimal welding sequence was gained through comparison and analysis. The results showed that the maximum residual stress on the plane of the welds was tensile stress after welding in a rectangular. The method of symmetry welding got smaller residual stress which could enhance the stability of the weldments, and starting from a longer welding path got smaller residual distortion of aluminum alloy.

2011 ◽  
Vol 399-401 ◽  
pp. 1806-1811
Author(s):  
Yong Hong Chen ◽  
Peng Chen ◽  
Ai Qin Tian

The finite element model of the roof of aluminum high-speed train was established, double ellipsoid heat source was employed, and heat elastic-plastic theory was used to simulate welding residual stress of the component under different welding sequence based on the finite element analysis software SYSWELD. The distribution law of welding residual stress was obtained. And the effects of the welding sequence on the value and distribution of residual stress was analyzed. The numerical results showed that the simulation data agree well with experimental test data. The maximum residual stress appears in the weld seam and nearby. The residual stress value decreases far away from the welding center. Welding sequence has a significant impact on the final welding residual stress when welding the roof of aluminum body. The side whose residual stress needs to be controlled should be welded first.


2013 ◽  
Vol 365-366 ◽  
pp. 261-267
Author(s):  
Zhi Ming Liu ◽  
Wei Gang Hu ◽  
Yue Chen

In order to study the influence of welding process and local detail design to the life of the metro bogie frame, this paper, in view of the tee joint, researched the superposition of residual stress and external load influence on the structure strength by the finite element simulation to establish mechanical structure and welding process co-design method. Based on the above research, the fatigue strength of the overlapping structure of welding frame socket plate and beam was improved, by the co-design of the groove angle and joint-welding sequence.


2010 ◽  
Vol 97-101 ◽  
pp. 1849-1852
Author(s):  
Tong Yue Wang ◽  
Ning He ◽  
Liang Li

Thin-walled structure is easy to vibrate in machining. The dynamic milling model of thin-walled workpiece is analyzed based on the analysis of degrees in two perpendicular directions of machine tool-workpiece system. In high speed milling of 2A12 aluminum alloy, the compensation method based on the modification of inertia effect is proposed and accurate cutting force coefficients are obtained. The machining system is divided into “spindle-cutter” and “workpiece-fixture” two sub-systems and the modal parameters of two sub-systems are acquired via modal analysis experiments. Finally, the stability lobes for high speed milling of 2A12 thin-walled workpiece are obtained by the use of these parameters. The results are verified against cutting tests.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Zhenjing Duan ◽  
Changhe Li ◽  
Wenfeng Ding ◽  
Yanbin Zhang ◽  
Min Yang ◽  
...  

AbstractAluminum alloy is the main structural material of aircraft, launch vehicle, spaceship, and space station and is processed by milling. However, tool wear and vibration are the bottlenecks in the milling process of aviation aluminum alloy. The machining accuracy and surface quality of aluminum alloy milling depend on the cutting parameters, material mechanical properties, machine tools, and other parameters. In particular, milling force is the crucial factor to determine material removal and workpiece surface integrity. However, establishing the prediction model of milling force is important and difficult because milling force is the result of multiparameter coupling of process system. The research progress of cutting force model is reviewed from three modeling methods: empirical model, finite element simulation, and instantaneous milling force model. The problems of cutting force modeling are also determined. In view of these problems, the future work direction is proposed in the following four aspects: (1) high-speed milling is adopted for the thin-walled structure of large aviation with large cutting depth, which easily produces high residual stress. The residual stress should be analyzed under this particular condition. (2) Multiple factors (e.g., eccentric swing milling parameters, lubrication conditions, tools, tool and workpiece deformation, and size effect) should be considered comprehensively when modeling instantaneous milling forces, especially for micro milling and complex surface machining. (3) The database of milling force model, including the corresponding workpiece materials, working condition, cutting tools (geometric figures and coatings), and other parameters, should be established. (4) The effect of chatter on the prediction accuracy of milling force cannot be ignored in thin-walled workpiece milling. (5) The cutting force of aviation aluminum alloy milling under the condition of minimum quantity lubrication (mql) and nanofluid mql should be predicted.


2021 ◽  
Vol 11 (13) ◽  
pp. 5881
Author(s):  
Shouhua Yi ◽  
Yunxin Wu ◽  
Hai Gong ◽  
Chenxi Peng ◽  
Yongbiao He

Aeronautical thin-walled frame workpieces are usually obtained by milling aluminum alloy plates. The residual stress within the workpiece has a significant influence on the deformation due to the relatively low rigidity of the workpiece. To accurately predict the milling-induced residual stress, this paper describes an orthogonal experiment for milling 7075 aluminum alloy plates. The milling-induced residual stress at different surface depths of the workpiece, without initial stress, is obtained. The influence of the milling parameters on the residual stress is revealed. The parameters include milling speed, feed per tooth, milling width, and cutting depth. The experimental results show that the residual stress depth in the workpiece surface is within 0.12 mm, and the residual stress depth of the end milling is slightly greater than that of the side milling. The calculation models of residual stress and milling parameters for two milling methods are formulated based on regression analysis, and the sensitivity coefficients of parameters to residual stress are calculated. The residual stress prediction model for milling 7075 aluminum alloy plates is proposed based on a back-propagation neural network and genetic algorithm. The findings suggest that the proposed model has a high accuracy, and the prediction error is between 0–14 MPa. It provides basic data for machining deformation prediction of aluminum alloy thin-walled workpieces, which has significant application potential.


2008 ◽  
Vol 571-572 ◽  
pp. 375-380 ◽  
Author(s):  
Winulf Machold ◽  
Peter Staron ◽  
Funda S. Bayraktar ◽  
Stefan Riekehr ◽  
Mustafa Koçak ◽  
...  

The effect of different welding sequences between a 4.5 mm thick AA 6156 T6 base plate and a 2 mm thick AA 6013 T6 clip – resembling a skin-clip joint of an airframe – using a 3.3 kW Nd:YAG laser is investigated. Under cyclic loading the breakdown of such T-joints happens at one end of the clip, which is due to local residual stress concentrations. Recent measurements indicated that tensile stresses could be lower at the run-in than at the run-out locations. For a deeper investigation of this effect sheets with different welding sequences were produced. One welding sequence was made with two starting points in the centre, and a second with starting points at the clip ends. Temperature measurements were made using thermocouples to verify the heat conditions for a finite element simulation of the welding process, which is used for predictions of the residual stress distribution. Actual values of the residual stress fields were determined by neutron diffraction. The influences of the welding sequence on the measured temperatures and the residual stresses are discussed.


2014 ◽  
Vol 24 (3) ◽  
pp. 657-664 ◽  
Author(s):  
Ding-fa FU ◽  
Chang-qing ZHOU ◽  
Can LI ◽  
Guan WANG ◽  
Luo-xing LI

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