Enhancement of Fatigue Life of Self-Piercing Riveted Joints by Coining

Manufacturing ◽  
2002 ◽  
Author(s):  
Zheng Jin ◽  
P. K. Mallick
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Aluminum Alloys ◽  
Automotive Industry ◽  
Spot Welding ◽  
Sheet Thickness ◽  
Compressive Stresses ◽  
Riveted Joints ◽  
Life Enhancement ◽  
Fatigue Life Enhancement

Self-piercing riveting is receiving attention in the automotive industry as an alternative to spot welding for body panels and structures, especially if they are made of aluminum alloys. In this paper, we explore the possibility of enhancing fatigue life of self-piercing riveted joints in 5754-O aluminum alloy sheets. Different sheet thickness combinations are considered. Coining is found to increase fatigue life significantly for self-piercing riveted joints in thinner sheets. However, the fatigue life enhancement is found to be less significant if the sheet thickness is in the range of 3 mm. The enhancement of fatigue life is attributed to residual compressive stresses around the coined area.

scholarly journals Spot-Weld Service Life Estimate Based on Application of the Interfacial Crack Concept

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2976 ◽  
Author(s):  
Ružica R. Nikolić ◽  
Jelena M. Djoković ◽  
Branislav Hadzima ◽  
Robert Ulewicz
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Service Life ◽  
Automotive Industry ◽  
Spot Welding ◽  
Interfacial Crack ◽  
Dissimilar Materials ◽  
Spot Weld ◽  
Elastic Materials ◽  
Linear Elastic

In the automotive industry, spot-welding is the most common method of joining components. Thus, determining the service life of spot-welds is of great importance in designing assemblies or structures. It is well-known that lately there has been a trend in the industry toward reducing the fuel consumption and harmful gasses emissions, as well as the weight of structures with the application of the lightweight materials, like aluminum alloys. In this paper, research is presented on the behavior of a spot-weld between the plates made of the two dissimilar materials—aluminum alloy and steel. In addition, the influence of the plates’ thickness and the weld nugget’s diameter on welds’ service life is presented. In this analysis, a concept of the interface crack between the two linear elastic materials was applied. Obtained results show that the plates’ thickness and the nugget’s size, as well as the working load, impose significant influences on the service life of a spot-weld between the two dissimilar materials.

Fatigue Life Enhancement of a D16at Aluminum Alloy for Aircraft Components with Fastener Holes

2020 ◽  
Vol 52 (1) ◽  
pp. 1-15
Author(s):  
G. V. Duncheva ◽  
J. T. Maximov ◽  
N. Ganev ◽  
A. P. Anchev
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Life Enhancement ◽  
Fatigue Life Enhancement

scholarly journals Effects of High Frequency Mechanical Impact on Fatigue Life of Semi-Automated Gas Metal Arc Welding (GTAW) of HSLA Butt Weld

2019 ◽  
Vol 269 ◽  
pp. 06002
Author(s):  
Salina Saidin ◽  
Dahia Andud ◽  
Yupiter H. P. Manurung ◽  
Muhd. Faiz Mat ◽  
Noridzwan Nordin ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Steel Structure ◽  
Welding Parameters ◽  
Butt Weld ◽  
Metal Arc Welding ◽  
Life Enhancement ◽  
Fatigue Life Enhancement

This paper deals with a comprehensive investigation of fatigue life enhancement on semiautomated Gas Metal Arc Welding (GTAW) butt weld joint which is found almost everywhere in Malaysia welding structure steel sectors. The selected material in this study was high strength low alloy steel S460G2+M commonly used extremely in steel structure due to its outstanding mechanical properties. In this investigation, the method for joining the butt weld was conducted by unprofessional welder using semi-automated GMAW. At first, suitable welding parameters were identified and formulated into welding procedure specification (WPS) qualification conforming to AWS D1.1 standard. The test specimens were prepared and tested to ensure the welding quality. Further, the HFMI using Pneumatic Impact Treatment (PIT) technique were applied at the weld toe of the butt weld as tool for fatigue life enhancement. To investigate the influence of HFMI/PIT on the fatigue strength, the specimens were undergone fatigue test using universal fatigue machine using a constant amplitude loading. Finally, the comparison of the fatigue strength of as welded and treated specimens to indicate the beneficial influence of the treatment. Yes, the conduction by unprofessional welder using semi-automatic GMAW, the findings showed the improvement of fatigue strength and slope of S-N curves. In addition, the fracture location of test specimen shows physically affected by shifting from critical weld transition to base metal. The tensile test and hardness value also showed a slight difference as compared to untreated specimens.

Fatigue life enhancement of welded stiffened S355 steel plates with noncircular openings

2015 ◽  
Vol 112 ◽  
pp. 93-107 ◽  
Author(s):  
Galya Duncheva ◽  
Jordan Maximov ◽  
Nikolaj Ganev ◽  
Marieta Ivanova
Keyword(s):  
Fatigue Life ◽  
Steel Plates ◽  
Life Enhancement ◽  
Fatigue Life Enhancement

Effect of Split-Sleeve Cold Expansion on the Fatigue Life of 7050-T7451 Aluminum Alloy

2014 ◽  
Vol 1082 ◽  
pp. 403-407 ◽  
Author(s):  
Hong Huang ◽  
Qing Yun Zhao ◽  
Feng Lei Liu
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Transgranular Fracture ◽  
Alloy Plate ◽  
Cold Expansion ◽  
Compressive Stresses ◽  
Aluminum Alloy Plate ◽  
Relationship Of ◽  
The Relationship

Split-sleeve cold expansion processing was employed on the 7050-T7451 aluminum alloy plate. Fatigue lives were compared according different expansion, then the relationship of fatigue life and expansion was analyzed. Residual stresses were measured with different expansion, and the fatigue fractograph was analyzed by SEM. The results show that the split-sleeve cold expansion can obtain longer life compared with the non-strengthen hole. When over the optimum expansion, fatigue life began to decrease. The maximum fatigue life increased to 2.92 times with 4.1% expansion. The maximum values of radial residual stresses grew with expansion. The depths of residual compressive stresses were more than 6mm with 2.6% and 4.1% expansion. The fatigue fractograph shows mixed transgranular fracture.

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