Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(Welding of pipelines). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Cranfield University

1. Modenesi, P. J. Statistical modelling of the narrow gap gas metal arc welding process.

Degree: PhD, 1990, Cranfield University

The J-laying technique for the construction of offshore pipelines requires a fast welding process that can produce sound welds in the horizontal-vertical position. The suitability of narrow gap gas metal arc welding (NG-GMA W) process for this application was previously demonstrated. The present programme studied the influence of process parameters on the fusion characteristics of NG-GMA welding in a range of different shielding gas compositions and welding positions. Statistical techniques were employed for both designing the experimental programme and to process the data generated. A partial factorial design scheme was used to investigate the influence of input variables and their interaction in determining weld bead shape. Modelling equations were developed by multiple linear regression to represent different characteristics of the weld bead. Transformation of the response variable based on the Cox-Box method was commonly used to simplify the model format. Modelling results were analysed by graphical techniques including surface plots and a multiplot approach was developed in order to graphically assess the influence of up to four input variables on the bead shape. Conditions for acceptable bead formation were determined and the process sensitivity to minor changes in input parameters assessed. Asymmetrical base metal fusion in horizontalvertical welding is discussed and techniques to improve fusion presented. At the same time, the interaction between the power supply output characteristic and the bead geometry was studied for narrow gap joints and the effect of shielding gas composition on both process stability and fusion of the base metal was assessed. An arc instability mode that is strongly influenced by arc length, power supply characteristic and shielding gas composition was demonstrated and its properties investigated. An optimized shielding gas composition for narrow gap process was suggested.

Subjects/Keywords: 670; Girth welding of pipelines

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Modenesi, P. J. (1990). Statistical modelling of the narrow gap gas metal arc welding process. (Doctoral Dissertation). Cranfield University. Retrieved from http://dspace.lib.cranfield.ac.uk/handle/1826/831 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237545

Chicago Manual of Style (16th Edition):

Modenesi, P J. “Statistical modelling of the narrow gap gas metal arc welding process.” 1990. Doctoral Dissertation, Cranfield University. Accessed January 25, 2020. http://dspace.lib.cranfield.ac.uk/handle/1826/831 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237545.

MLA Handbook (7th Edition):

Modenesi, P J. “Statistical modelling of the narrow gap gas metal arc welding process.” 1990. Web. 25 Jan 2020.

Vancouver:

Modenesi PJ. Statistical modelling of the narrow gap gas metal arc welding process. [Internet] [Doctoral dissertation]. Cranfield University; 1990. [cited 2020 Jan 25]. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/831 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237545.

Council of Science Editors:

Modenesi PJ. Statistical modelling of the narrow gap gas metal arc welding process. [Doctoral Dissertation]. Cranfield University; 1990. Available from: http://dspace.lib.cranfield.ac.uk/handle/1826/831 ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237545


University of Alberta

2. Lecoanet, Alexandre J L. Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes.

Degree: MS, Department of Chemical and Materials Engineering, 2016, University of Alberta

The submerged-arc welding (SAW) process is used extensively in the manufacturing of pipes. The heat flow introduced by the welding operation has a significant impact on the properties of both the weld metal and the heat affected zone (HAZ). The work presented in this thesis aims to develop a numerical heat flow model to predict the temperature profile in piece welded using SAW as a function of the welding parameters. Measurement were done using instrumented thermocouples during an operation of SAW with one electrode. The models were then compared to the measurements and a sensitivity analysis was carried out on the density, the specific heat, the parameter called “ff” in the double ellipsoid model, and the Neumann boundary condition. The three models used are a point source model giving results similar to Rosenthal’s results, a model using a double ellipsoid heat source with constant thermal properties, and a model using a double ellipsoid heat source with varying thermal properties. The presence of the thermocouples linked to the data acquisition system used in the experiment disturbed the weld but workable data were still extracted. Then the comparison between the measurement and the simulations showed that the most accurate model is the one using a double ellipsoid heat source with varying thermal properties. It predicts well the heating and the cooling phases of all the temperature profiles recorded but it predicts the peak well only for the thermocouples located around 12 mm from the center of the plate closer it overestimates the peak. The sensitivity analysis showed that the most sensitive parameters are the thermal properties. It also showed that the parameter called “ff” in Goldak’s approach is sensitive. The Neumann boundary condition is not a sensitive parameter. Also when measurements are done using thermocouples close to the knowing the exact location of the thermocouples is crucial.

Subjects/Keywords: Submerged arc welding; SAW; Modelling of submerged arc welding; Modelling of SAW; Modelling; Finite element method; FEM; Finite element method SAW; Thermal profile; Temperature profile; Modelling temperature profile; Instrumented thermocouples; Varying thermal properties; Simulation; Simulation of SAW; Simulation of welding; FEM modelling of SAW; Quasi-steady state; Heat transfer in welding; Point source; Double ellipsoid source; Two electrode welding; Welding with two electrodes; Instrumented welds; Sensitivity of the thermal properties; Welding of X70; Welding of pipelines; Statistical analysis; Bead shape parameters; Removing outliers; Simulation of welding with COMSOL; Mixed boundary condition; Simulation with two point sources; Infinite elements; Application of infinite elements to welding; Heat tranfer in moving coordinate system; Welding; Multiple electrode welding; Sensitivity analysis; Sensitivity analysis on submerged arc welding; Sensitivity analysis on SAW; Temperature measurement during a welding operation; Temperature measurement during submerged arc welding; Temperature measurement during SAW; Modelling temperature profile during welding; Modelling temperature profile during submerged arc welding; Modelling temperature profile during SAW

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Lecoanet, A. J. L. (2016). Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/czk51vg98f

Chicago Manual of Style (16th Edition):

Lecoanet, Alexandre J L. “Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes.” 2016. Masters Thesis, University of Alberta. Accessed January 25, 2020. https://era.library.ualberta.ca/files/czk51vg98f.

MLA Handbook (7th Edition):

Lecoanet, Alexandre J L. “Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes.” 2016. Web. 25 Jan 2020.

Vancouver:

Lecoanet AJL. Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes. [Internet] [Masters thesis]. University of Alberta; 2016. [cited 2020 Jan 25]. Available from: https://era.library.ualberta.ca/files/czk51vg98f.

Council of Science Editors:

Lecoanet AJL. Finite Element Model of the Thermal Profile During Submerged Arc Welding with One and Two Electrodes. [Masters Thesis]. University of Alberta; 2016. Available from: https://era.library.ualberta.ca/files/czk51vg98f

.