Effects of stress concentration on the fatigue strength of 7003-T5 aluminum alloy butt joints with weld reinforcement

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540023 ◽  
Author(s):  
Zongtao Zhu ◽  
Yuanxing Li ◽  
Mingyue Zhang ◽  
Chen Hui
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Fatigue Testing ◽  
Gas Metal Arc Welding ◽  
Cyclic Stress ◽  
Butt Joint ◽  
Al Alloy ◽  
Butt Joints ◽  
Butt Weld ◽  
Metal Arc Welding

7003-T5 Aluminum ( Al ) alloy plates with a thickness of 5 mm are welded by gas metal arc welding (GMAW) method in this work. In order to investigate the influence of stress concentration introduced by weld reinforcement on fatigue strength, the stress concentration factor of the butt joint is calculated. Microscopic and X-ray techniques were utilized to make sure there are no weld defects with large size in butt weld, which can induce extra stress concentration. The cyclic stress – number of cycles to failure (S–N) curves of the joints with and without the welder were obtained by fatigue testing, and the results show that the fatigue strength of 7003-T5 Al alloy butt joints with the weld reinforcement is 50 MPa, which is only 45% of the joints without the weld reinforcement. Fracture surface observation indicated that the fatigue source and propagation are dissimilar for the specimens with and without the welder due to the stress concentration at the weld root. The stress concentration with a factor of 1.7 has great effect on the fatigue strength, but little influence on the tensile strength.

Effect of Different Filler Towards Welding of AA6061 Al Alloy by X-Ray CT Scan

2010 ◽  
Vol 146-147 ◽  
pp. 1402-1405 ◽  
Author(s):  
Che Lah Nur Azida ◽  
Azman Jalar ◽  
Norinsan Kamil Othman ◽  
Nasrizal Mohd Rashdi ◽  
Md Zaukah Ibel
Keyword(s):  
Aluminum Alloy ◽  
Ct Scan ◽  
Welded Joint ◽  
Gas Metal Arc Welding ◽  
Butt Joint ◽  
Al Alloy ◽  
X Ray ◽  
Metal Arc Welding ◽  
Joint Quality ◽  
Filler Metals

AA6061 Aluminum alloy welded joint using two different filler metals were studied by using X-ray CT-Scan. The filler metals ER 4043 and ER 5356 were used in this present work in order to investigate the effect of using different filler metals on the welded joint quality of AA 6061 aluminum alloy in welded zone microstructure. Gas metal arc welding (GMAW) technique and V grove butt joint with four layers and five passes welded joint were performed. From this investigation, it is found that AA6061 with ER 4043 showed less distribution of porosity compared to AA6061 with ER 5356 welded joint confirmed by X-ray Ct-Scan. The decreasing of porosities and presence of very fine grains in weld region area with ER 5356 compared to ER 4043 will be discussed in term of microstructure analysis.

An Estimation Formula of the Stress Concentration Factor of the Butt-Welded Joint

2007 ◽  
Vol 353-358 ◽  
pp. 1995-1998
Author(s):  
Byeong Choon Goo
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Gas Metal Arc Welding ◽  
Element Analysis ◽  
Butt Weld ◽  
Estimation Formula ◽  
Metal Arc Welding ◽  
Concentration Factors ◽  
Stress Concentration Factors

The purpose of this paper is to develop an estimation formula of stress concentration factors of butt-welded components under tensile loading. To investigate the influence of weld bead profiles on stress concentration factors of double V groove butt-welded joints, butt-welded specimens were made by CO2 gas metal arc welding. And the three main parameters, the toe radius, flank angle and bead height were measured by a profile measuring equipment. By using the measured data, the influence of three parameters on the stress concentration factors was investigated by a finite element analysis. It is shown that the three parameters have similar effects on the stress concentration factors. According to the simulation results, a formula to estimate the stress concentration factors of butt-weld welded structures was proposed and the estimated concentration factors from the formula were compared with the results obtained by the finite element analysis. The two results are in a good agreement.

Evaluation by FEM of the Influence of the Preheating and Post-Heating Treatments on Residual Stresses in Welding

2014 ◽  
Vol 627 ◽  
pp. 93-96 ◽  
Author(s):  
Raffaele Sepe ◽  
Enrico Armentani ◽  
Giuseppe Lamanna ◽  
Francesco Caputo
Keyword(s):  
Temperature Distribution ◽  
Residual Stresses ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Element Model ◽  
Butt Joint ◽  
Temperature Fields ◽  
Heating Process ◽  
Butt Weld ◽  
Metal Arc Welding

During the last few years various experimental destructive and non-destructive methods were developed to evaluate residual stresses. However it is impossible to obtain a full residual stress distribution in welded structures by means of experimental methods. This disadvantage can be solved by means of computational analysis which allows to determine the whole stress and strain fields in complex structures. In this paper the temperature distribution and residual stresses were determined in a single-pass butt joint welded by GMAW (Gas Metal Arc Welding) process by finite element model (FEM). A 3D finite parametric element model has been carried out to analyze temperature distribution in butt weld joints and thermo-mechanical analyses were performed to evaluate resulting residual stresses. Temperature fields have been investigated by varying an initial preheating treatment. Moreover the technique of “element birth and death” was adopted to simulate the process of filler metal addition The high stresses were evaluated, with particular regard to fusion zone and heat affected zone. The influence of preheating and post-heating treatment on residual stresses was investigated. The residual stresses decrease when preheating temperature increases. The maximum value of longitudinal residual stresses without pre-heating can be reduced about 12% and 38% by using the preheating and post-heating process respectively.

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.

Back Bead Characteristics during Butt Welding of a Thick Plate for Various Backing Conditions

2010 ◽  
Vol 654-656 ◽  
pp. 350-353 ◽  
Author(s):  
Cheol Hee Kim
Keyword(s):  
Fatigue Strength ◽  
Arc Welding ◽  
Thick Plate ◽  
Gas Metal Arc Welding ◽  
Butt Joint ◽  
Butt Welding ◽  
Weld Defects ◽  
Metal Arc Welding ◽  
Welded Structure ◽  
Job Site

In a welded structure, thick plates are joined by multi-pass welding in the butt joint. During the first pass of multi-pass welding, burn-through, lack of fusion, and incomplete penetration were readily found as weld defects. Accordingly, the backing condition should be carefully selected in welding of a thick plate, because improper backing conditions lead to weld defects. In the job site, a steel backing strip is usually adopted, although it reduces the fatigue strength. No backing conditions or removable backing is recommended to increase the fatigue strength, but selection of the proper backing and welding conditions is complicated. In this study, several backing methods, such as ceramic backing, water-cooled copper backing, and even the use of no backing, were investigated during GMA (Gas Metal Arc) welding of a thick steel plate. The gas metal arc welding conditions were established for each backing method, and the bead shape and mechanical properties were examined after welding.

Arc Fusion Welding of Mg-Al2Ca-Added Al 5xxx Alloys

2017 ◽  
Vol 371 ◽  
pp. 25-30
Author(s):  
Min Jung Kang ◽  
Cheol Hee Kim
Keyword(s):  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Al Alloys ◽  
Fusion Welding ◽  
Al Alloy ◽  
Alloy Specimen ◽  
Metallurgical Properties ◽  
Metal Arc Welding ◽  
Al 5052 Alloy

When casting ECO Al alloys, Mg-Al2Ca is used as a substitute for elemental Mg during the alloying process. Several previous studies have determined the mechanical and metallurgical properties of the ECO Al 5052 alloy. In this study, the weldability of the ECO Al 5052 alloy was determined. Gas metal arc welding was performed, and the resultant mechanical and metallurgical aspects of the welds in ECO Al 5052 alloy and commercial Al 5052 alloy were examined. In comparison to the commercial Al 5052 alloy specimen, the welds produced in the ECO Al 5052 alloy exhibited a very narrow heat-affected zone and were not softened through grain coarsening. Consequently, almost 100% joint efficiencies were observed in ECO Al alloy welds, in comparison to joint efficiencies of only 82% in conventional Al 5052 alloy welds.

Residual Stress Depth-Profiling in Shot-Peened Al Alloy Components Subjected to Fatigue Testing

2010 ◽  
Vol 638-642 ◽  
pp. 2464-2469 ◽  
Author(s):  
Cristy Leonor Azanza Ricardo ◽  
G. Degan ◽  
M. Bandini ◽  
Paolo Scardi
Keyword(s):  
Residual Stress ◽  
Fatigue Testing ◽  
Depth Profiling ◽  
Cyclic Stress ◽  
Al Alloy ◽  
Stress Profile ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Stress Profile ◽  
Number Of Cycles

The residual stress profile in a shot-peened Al alloy component was studied by a recently proposed method based on the known procedure of progressive thinning and X-ray Diffraction measurements. The effect the cyclic stress on the fatigue life was studied in detail, showing the correlation between nominal load and residual stress relaxation. Besides showing the expected decrease of compressive stress with the load and number of cycles, the present work highlights the importance of changes in the through-the-thickness residual stress distribution.

Mechanical Properties of 5083 Aluminium Welds after Manual and Automatic Pulsed Gas Metal Arc Welding Using E5356 Filler

2010 ◽  
Vol 654-656 ◽  
pp. 2560-2563 ◽  
Author(s):  
Kalenda Mutombo ◽  
Madeleine du Toit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Stress Concentration ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Fatigue Properties ◽  
Filler Wire ◽  
Metal Arc Welding ◽  
Weld Toe ◽  
Fully Automatic

Semi-automatic and automatic pulsed gas metal arc welding (GMAW) of aluminium alloy 5083 with ER5356 filler wire causes considerable softening in the weld. The tensile strength of dressed automatic welds approaches that of the base metal, but the stress concentration caused by the weld toe in undressed semi-automatic welds reduced the tensile strength significantly. Fully automatic welds displayed improved fatigue properties compared to semi-automatic welds.

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