scholarly journals Influence of Residual Stress on Fatigue Weak Areas and Simulation Analysis on Fatigue Properties Based on Continuous Performance of FSW Joints

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 284 ◽  
Author(s):  
Guoqin Sun ◽  
Xinhai Wei ◽  
Jiangpei Niu ◽  
Deguang Shang ◽  
Shujun Chen
Keyword(s):  
Residual Stress ◽  
Simulation Analysis ◽  
Stress Measurement ◽  
Correlation Method ◽  
Fatigue Property ◽  
Joint Model ◽  
Fatigue Properties ◽  
Hardness Profile ◽  
Continuous Performance ◽  
Friction Stir

The fatigue weak area of aluminum alloy for a friction stir-welded joint is investigated based on the hardness profile, the residual stress measurement and the simulation analysis of fatigue property. The maximum residual stresses appeared at the heat-affected zone of the joint in the fatigue damage process, which was consistent with the fracture location of the fatigue specimen. The fatigue joint model of continuous performance is established ignoring the original negative residual stress; considering that it will be relaxed soon when the joint is under tension-tension cyclic loading. The fatigue parameters of joint model is based on the static mechanical properties of the joint that obtained from the micro-tensile tests and four-point correlation method. The predicted results for the fatigue weak locations and fatigue lives based on the continuous performance joint model are closer to the fatigue experimental results by comparison with the simulation results of the partitioned performance joint model.

RESIDUAL STRESS MEASUREMENT IN FRICTION STIR WELDS USING LASER ULTRASONICS

2009 ◽  
Author(s):  
D. Lévesque ◽  
L. Dubourg ◽  
M. Lord ◽  
M. Jahazi ◽  
A. Blouin ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Laser Ultrasonics ◽  
Friction Stir

Analysis on the Residual Stresses in the Aluminum Alloy Friction Stir Welded Joints

2011 ◽  
Vol 291-294 ◽  
pp. 958-963
Author(s):  
Li Jie Cao
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Residual Stresses ◽  
Simulation Analysis ◽  
Engineering Application ◽  
Stress Fields ◽  
Weld Strength ◽  
Technological Parameters ◽  
Friction Stir ◽  
Wide Range

The residual stress fields can have strong influences on the integrity and performance of friction stir welded aluminum alloy structure, comprehensive insight into the residual stress distribution is the key to the Friction stir welding (FSW) engineering application for a wide range of materials and thicknesses improving the weld strength and fatigue life. In this paper, the current state of the residual stresses in the FSW aluminum alloy joints is reviewed, The focus is on recent advances of experimental research, the results of numerical simulation analysis, and the effects of the technological parameters(welding speed, rotational speed, shoulder geometry et al.) on residual stress fields was evaluated. In the end, The controlling technique of residual stresses from published literatures is summarized.

scholarly journals Effect of Residual Stress on the Mechanical Properties of FSW Joints with SUS409L

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yeong-Seok Lim ◽  
Sang-Hyuk Kim ◽  
Kwang-Jin Lee
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Stress Measurement ◽  
Charpy Impact ◽  
Stir Zone ◽  
Hole Drilling ◽  
Friction Stir ◽  
Compressive Residual Stresses

This study was performed to investigate both the residual stress distribution and the effect of the residual stress formed at the welding region on the mechanical properties of the friction stir welded joints with 409L stainless steel sheets. Residual stress measurement with hole-drilling method; mechanical property evaluation including tensile test, Charpy impact test, and fatigue test; and microstructure observation were conducted. It has got no residual stresses to speak of at the center region of the stir zone because the stored stresses are released in the process of the dynamic recrystallization, while a small quantity of compressive residual stresses is formed at the surface region of the stir zone because of strong compression reaction by the tool shoulder. A considerable amount of compressive residual stresses is formed at the thermomechanical affected zone because of the synergy between the thermal expansion due to the heat conduction from the stir zone and mechanical compression by the tool. The formation of residual stresses shows a similar tendency between the advancing side and the retreating side. Both the mitigation of residual stress in the stir zone and the formation of compressive residual stress in the thermomechanical affected zone contribute to the improvement of the mechanical properties of the friction stir welded joints.

Improvement of Fatigue Properties in a Cast Aluminum Alloy by Roller Burnishing and Friction Stir Processing

2014 ◽  
Vol 891-892 ◽  
pp. 662-667 ◽  
Author(s):  
Yuki Nakamura ◽  
Masaki Nakajima ◽  
Hiroaki Masuda ◽  
Toshifumi Kakiuchi ◽  
Yoshihiko Uematsu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Friction Stir Processing ◽  
Compressive Residual Stress ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Bending Fatigue ◽  
Friction Stir

Roller burnishing (RB) and friction stir processing (FSP) were applied to a cast aluminum alloy, AC4CH-T6 (equivalent to A356-T6), to improve the fatigue properties. In roller burnished specimens, Vickers hardness was increased until the depth of 60μm compared with that of the as-cast specimens, resulting in work-hardening by RB. The compressive residual stress on the surface of the roller burnished specimens was also increased from 35MPa to 132MPa. In order to investigate the effect of RB on the fatigue properties, rotary bending fatigue tests have been performed using the roller burnished and the as-cast specimens. The roller burnished specimens exhibited higher fatigue strength than the untreated specimens. It is due to the increase in hardness and compressive residual stress by RB. In addition, plane bending fatigue tests have been performed using the friction stir processed and untreated specimens. Fatigue strengths of the friction stir processed specimens were highly improved compared with untreated specimens as the results of the elimination of casting defects by FSP. However, the crack growth rates of the friction stir processed specimens were faster than those of untreated specimens. It is due to the softening of the material by heat input during the FSP.

Fabrication of FSW Tool Pins Through Turning of H13 Tool Steel: A Comparative Analysis for Residual Stresses

2021 ◽  
pp. 1-16
Author(s):  
Ravi Butola ◽  
Ravi Pratap Singh ◽  
Naman Choudhary ◽  
K. K. S. Mer ◽  
Jitendra Bhaskar ◽  
...  
Keyword(s):  
Residual Stress ◽  
Shear Stress ◽  
Tool Steel ◽  
Compressive Residual Stress ◽  
Stress Measurement ◽  
Positive Impact ◽  
Cnc Machine Tools ◽  
Friction Stir ◽  
H13 Tool Steel ◽  
Residual Shear Stress

In the present research, measurement of residual stress induced during turning and threading operations for the fabrication of two types of pin profiled friction stir processing/welding (FSP/FSW) tools, i.e. cylindrical profiled pin tool and cylindrical threaded profiled pin tool, is being dealt with. Workpiece was chosen to be H13 tool steel with a diameter of 22[Formula: see text]mm and 110[Formula: see text]mm length. Turning and threading was done on CNC machine tools using CNMG 12404-THM uncoated tungsten carbide cutting tool. For residual stress measurement of the workpieces, an XRD-based Pulsetec[Formula: see text]-X360n portable residual stress analyzer setup was used. The experimental results show that the cylindrical pin profile tool had a compressive residual stress of [Formula: see text][Formula: see text]MPa and compressive residual shear stress of [Formula: see text][Formula: see text]MPa, while the cylindrical threaded pin profile tool had a compressive residual stress of [Formula: see text][Formula: see text]MPa (51.8% more) and compressive residual shear stress of [Formula: see text][Formula: see text]MPa (40% less). It has been concluded that due to threading operation on the cylindrical threaded pin profile, the value of residual stress is more in it, and since the stress is compressive in nature, it would have a better positive impact while doing FSP/FSW than that of the cylindrical profiled pin tool.

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