Transverse and Longitudinal Stress Analysis in Reinforced Welded Oil Branched Pipes

Welding process results in the non-uniform distribution of heat. Combined with thermal strain, plastic deformation and welding-induced distortion, it causes important problems such as failure. This study models welding process in a 12×16 split tee junction using finite element. This junction is a reinforcing branch used in the hot taping of oil pipe line. The model is studied in 3D state. This zone, i.e. heat affected zone (HAZ) is of high importance due to the existence of a severe temperature gradient and stress in the vicinity of HAZ. This study analyses single pass butt welding with a cooling time of 2700 seconds. In order to apply boundary conditions to the model, the studied structure should be in Free State according to practical procedure. The main aim of this simulation is to analyse Longitudinal and transverse residual stresses originated from co-directional and opposite-directional welding. This joint is formed of two semicircles welded to each other as linear single pass welding. Two welders simultaneously welded both sides of the pipe.

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Application of Similitude Theory for Welding Deformation Prediction of Large Hydraulic Excavator

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.26-28.448 ◽

2010 ◽

Vol 26-28 ◽

pp. 448-451 ◽

Cited By ~ 1

Author(s):

Qing Hua Dai ◽

Peng Ji ◽

Chen Bo Yin ◽

Di Sheng Yi ◽

Bin Wang ◽

...

Keyword(s):

Plastic Deformation ◽

Deformation Zone ◽

Welding Process ◽

Plastic Deformation Zone ◽

Hydraulic Excavator ◽

Welding Deformation ◽

Single Pass ◽

Welding Sequence ◽

Elastic And Plastic Deformation ◽

Similitude Theory

A high Computational Complexity of welding deformation Simulation for large hydraulic excavator is visible. Similitude theory is a better way to solve the problem. When neglecting the energy change caused by elastic and plastic deformation, and supposing the geometry similitude of plastic deformation zone, and having the same stress for the plastic deformation zone of the same materials, similar rules of the single-pass welding based on temperature field had been deduced. But we don’t know whether they are effectual for the multi-layer-pass welding. For validating it, a numerical simulation was carried out through simulating the welding process of large hydraulic excavator’s swing arm. And we got the better results. The similar rules deduced on the single-pass welding are also applicable for multi-layer-pass welding under the conditions of the same weld numbers and the same welding sequence.

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Experimental studies on the possibility of using a pulsed laser for spot welding of thin metallic foils

Open Engineering ◽

10.1515/eng-2020-0076 ◽

2020 ◽

Vol 10 (1) ◽

pp. 674-680

Author(s):

Piotr Sęk

Keyword(s):

Experimental Studies ◽

Pulsed Laser ◽

Welding Process ◽

Pulse Mode ◽

Weld Strength ◽

Spot Welds ◽

Butt Welding ◽

Strength Tests ◽

Metallic Foils ◽

The Impact

AbstractThe purpose of the experiment was to study the influence of the laser beam in pulse mode on metallic foils in order to obtain a spot weld. The welding process was carried out using the overlap weld method, using spot welds in various quantities. The Nd - YAG BLS 720 pulsed laser was used to conduct the experiment. The impact of the number of spot welds on the value of force needed to break the sample was examined. A number of measurements were carried out to determine the best process parameters. Butt welding and overlap welding were also performed using a continuous weld consisting of spot welds. Weld strength tests were performed to select the most appropriate parameters for the process under consideration.

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Hybrid laser-arc welding of laser- and plasma-cut 20-mm-thick structural steels

Welding in the World ◽

10.1007/s40194-022-01255-y ◽

2022 ◽

Author(s):

Ömer Üstündağ ◽

Nasim Bakir ◽

Sergej Gook ◽

Andrey Gumenyuk ◽

Michael Rethmeier

Keyword(s):

Laser Beam ◽

Arc Welding ◽

Laser Beam Welding ◽

Digital Camera ◽

Welding Process ◽

Beam Power ◽

Beam Diameter ◽

Hybrid Laser Arc Welding ◽

Single Pass ◽

New Findings

AbstractIt is already known that the laser beam welding (LBW) or hybrid laser-arc welding (HLAW) processes are sensitive to manufacturing tolerances such as gaps and misalignment of the edges, especially at welding of thick-walled steels due to its narrow beam diameter. Therefore, the joining parts preferably have to be milled. The study deals with the influence of the edge quality, the gap and the misalignment of edges on the weld seam quality of hybrid laser-arc welded 20-mm-thick structural steel plates which were prepared by laser and plasma cutting. Single-pass welds were conducted in butt joint configuration. An AC magnet was used as a contactless backing. It was positioned under the workpiece during the welding process to prevent sagging. The profile of the edges and the gap between the workpieces were measured before welding by a profile scanner or a digital camera, respectively. With a laser beam power of just 13.7 kW, the single-pass welds could be performed. A gap bridgeability up to 1 mm at laser-cut and 2 mm at plasma-cut samples could be reached respectively. Furthermore, a misalignment of the edges up to 2 mm could be welded in a single pass. The new findings may eliminate the need for cost and time-consuming preparation of the edges.

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Preliminary Research on Influence of Welding Parameters Strength at Welded Joints in Ribbed Reinforcing Steel

Tehnički glasnik ◽

10.31803/tg-20200303111417 ◽

2020 ◽

Vol 14 (3) ◽

pp. 369-374

Author(s):

Željko Bilić ◽

Ivan Samardžić ◽

Nedjeljko Mišina ◽

Katarina Stoić

Keyword(s):

Welded Joint ◽

Welding Process ◽

Welding Parameters ◽

Non Destructive Testing ◽

Destructive Testing ◽

Butt Welding ◽

Control Interface ◽

High Level ◽

Non Destructive

As already known, no proper control or process control parameter which absolutely guarantees a high level quality of joints made by electro-resistive welding has been established so far, especially when all possible parameters are taken into account during the welding process. Due to the process of butt-welding being very short-lived, ensuring quality of the joints is a difficult and under-researched problem. The application of non-destructive testing methods to the control interface joints is also not reliable. Therefore, further research in this area should concentrate on studying the influence of basic welding parameters, and calculating their direct or indirect impact can serve to achieve a highquality welded joint with for practice sufficient accuracy.

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Parameter Optimization and System Design of the Welding Power Supply for Resistance-Butt Welding of Nuclear Fuel Rod

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.201-203.2661 ◽

2011 ◽

Vol 201-203 ◽

pp. 2661-2666

Author(s):

Fang Quan Chen ◽

Zu Wei Lin ◽

Guo Wei Liang

Keyword(s):

Nuclear Fuel ◽

Power Supply ◽

Welding Process ◽

Capacitor Discharge ◽

Butt Welding ◽

Fuel Rod ◽

Current Curve ◽

Bridge Rectifier ◽

And Control ◽

Welding Power Supply

This paper firstly gives a brief description about the principle of resistance-butt welding of nuclear fuel rod, and it points out that the power supply is a key technology for welding process. According to the welding process and the welded material properties, capacitor discharge power supply is devised as welding power supply. The design of charging circuit of single-phase bridge rectifier with SCR and control circuit is finished. The process of power discharge is simulated and the parameters (capacitance C, charging voltage uc) are optimized with Matlab. By the welding experiments, it shows that the output current curve is suitable for resistance-butt welding of nuclear fuel rods, and the test results of welding samples entirely consistent with process requirements.

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Characterization of Surface Defects Associated with Flash Butt-Welded Pearlitic Rails and their Contribution to Overload and Fatigue Failures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.83-86.1262 ◽

2009 ◽

Vol 83-86 ◽

pp. 1262-1269 ◽

Cited By ~ 1

Author(s):

Mostafa Mousavizade ◽

Hassan Farhangi

Keyword(s):

Surface Defects ◽

Weld Zone ◽

Welding Process ◽

Electrical Heating ◽

Main Concern ◽

Zone Formation ◽

Butt Welding ◽

Fatigue Failures

Generally about 80 percent of railway tracks are welded by flash-butt welding that consists of electrical heating and hydraulic forging. Fracture of rails specially weld zone fractures are of main concern because of potential risk of a catastrophic derailment. In this paper, surface defects associated with flash butt welding process are examined. Metallographic and fractographic studies show various defects can be formed at the surface of weld zone. Formation mechanism of these defects and their contribution to the observed fatigue and overload weld failures are discussed. Fracture mechanics is also utilized to clarify the role of these defects in fatigue and overload failures.

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Acoustic Information Acquisition and Time Domain Analysis on Alternating Current Rail Flash Butt Welding

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.239-240.16 ◽

2012 ◽

Vol 239-240 ◽

pp. 16-20

Author(s):

Qi Bing Lv ◽

Ke Li Tan ◽

Xi Zhang ◽

Jian Chen ◽

Guo Qing Liu

Keyword(s):

Time Domain ◽

Acoustic Signal ◽

Information Acquisition ◽

Welding Process ◽

Welding Current ◽

Time Domain Analysis ◽

Mean Square ◽

Butt Welding ◽

The Mean ◽

The Stability

Based on the mobile rail flash butt welding machine UN5-150ZB, the synchronous data acquisition hardware system was designed to collect welding current, welding voltage and flash acoustic signal in welding process, and the software platform with the functions of signal collecting, waveform display and data operation was developed by higher-level programming language LabVIEW. After the welding current, welding voltage and flash acoustic signal in welding process had been collected, the mean, variance and mean square value of flash acoustic signal in time-domain were analyzed. Through comparison, the relationship between these characteristics and the stability of flash was analyzed. The result shows that the changes of mean and variance of flash acoustic signal are not obvious, and do not correlate with stability of flash, but the mean square value in time domain is closely associated with the stability of flash, and the stability of flash can be indicated by the mean square value.

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Formation of Intermetallic Compounds in Dissimilar Friction Spot Weld of Al to Mg Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.765.731 ◽

2013 ◽

Vol 765 ◽

pp. 731-735 ◽

Cited By ~ 1

Author(s):

Uceu Suhuddin ◽

Vanessa Fischer ◽

Jorge dos Santos

Keyword(s):

Plastic Deformation ◽

Spot Welding ◽

Dwell Time ◽

Welding Process ◽

Eutectic Structure ◽

Mixed Solution ◽

Microstructure Formation ◽

Friction Spot Welding ◽

Welding Cycle ◽

Insight Into

In the present study, friction spot welding has been used for joining dissimilar AA5754 aluminum to AZ31 magnesium alloys. To get more insight into the microstructure, stop-action experimentation was employed. The welding cycle was forced to stop during the dwell time, and subsequently, the weld was quenched by pouring a mixed solution of ice and water to freeze the microstructure. Formation of the liquid phase leading to a formation of brittle intermetallic compound has been studied. Microstructural analyses reveal that formation of intercalated layers and a high density of grain boundaries induced by plastic deformation enhance the formation of eutectic structure during the welding process.

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