Application of welding simulation to block joints in shipbuilding and assessment of welding-induced residual stresses and distortions
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During ship design, welding-induced distortions are roughly estimated as a function of the size of the component as well as the welding process and residual stresses are assumed to be locally in the range of the yield stress. Existing welding simulation methods are very complex and time-consuming and therefore not applicable to large struc-tures like ships. Simplified methods for the estimation of welding effects were and still are subject of several research projects, but mostly concerning smaller structures. The main goal of this paper is the application of a multi-layer weld-ing simulation to the block joint of a ship structure. When welding block joints, high constraints occur due to the ship structure which are assumed to result in accordingly high residual stresses. Constraints measured during construction were realized in a test plant for small-scale welding specimens in order to investigate their and other effects on the residual stresses. Associated welding simulations were successfully performed with fine-mesh finite element models. Further analyses showed that a courser mesh was also able to reproduce the welding-induced reaction forces and hence the residual stresses after some calibration. Based on the coarse modeling it was possible to perform the welding simulation at a block joint in order to investigate the influence of the resulting residual stresses on the behavior of the real structure, showing quite interesting stress distributions. Finally it is discussed whether smaller and idealized models of definite areas of the block joint can be used to achieve the same results offering possibilities to consider residual stresses in the design process.
Abstract
During ship design, welding-induced distortions are roughly estimated as a function of the size of the component as well as the welding process and residual stresses are assumed to be locally in the range of the yield stress. Existing welding simulation methods are very complex and time-consuming and therefore not applicable to large struc-tures like ships. Simplified methods for the estimation of welding effects were and still are subject of several research projects, but mostly concerning smaller structures. The main goal of this paper is the application of a multi-layer weld-ing simulation to the block joint of a ship structure. When welding block joints, high constraints occur due to the ship structure which are assumed to result in accordingly high residual stresses. Constraints measured during construction were realized in a test plant for small-scale welding specimens in order to investigate their and other effects on the residual stresses. Associated welding simulations were successfully performed with fine-mesh finite element models. Further analyses showed that a courser mesh was also able to reproduce the welding-induced reaction forces and hence the residual stresses after some calibration. Based on the coarse modeling it was possible to perform the welding simulation at a block joint in order to investigate the influence of the resulting residual stresses on the behavior of the real structure, showing quite interesting stress distributions. Finally it is discussed whether smaller and idealized models of definite areas of the block joint can be used to achieve the same results offering possibilities to consider residual stresses in the design process.
참고문헌 (20)
- Böllinghaus, T., "Determination of crack-critical shrinkage restraints and hydrogen distribution in welded joints by numerical simulation (in German)", 박사, pp.1995
- Choo, R.T., "The possible role of turbulence in GTA weld pool behavior", Welding Journal Research Supplement, 74(2), pp.25s~31s (1994)
- Fricke, W., "Application of welding simulation to block joints in shipbuilding and assessment of welding-induced residual stresses (in German)" (2011), Schiffahrts- Verlag‚‘Hansa’
- Goldak, M., "A new finite element model for welding heat sources", Metallurgical Trans-action B, 15B, pp.299~305 (1984)
- Haibach, E., "Betriebsfestigkeit - Verfahren und Daten zur Bauteilberechnung (Fatigue strength - procedures and data for analysis of components)" (2002), Springer-Verlag
- Hoffmeister, H., "Concept and procedure description of the IRC test for assessing hydrogen assisted weld cracking", Steel Research(AEW), 57(7), pp.345~347 (1986)
- Welding of large gaps at butt joints of shipbuilding blocks (in German), "Huismann, G.", Universität der Bundeswehr, ~, pp.Final Report of BMBF Research Project 03SX133B (2001), Teilprojekt P3.1
- Karlsson, L., "Modeling of Casting, Welding and Advanced Solidification Processes V: 5th In-ternational conference on modeling of casting and welding processes" (1990), Minerals, Metals & Materials Society
- Lancaster, J. F., "The physics of welding" (1986), Pergamon Press
- Lowke, J. J., "Theory of free-burning arc columns including the influence of the cathode", Journal of Physics D Applied Physics, 25(11), pp.1600~1606 (1992)
- Osawa, N., "Study on shell-solid coupling FE analysis for fa-tigue assessment of ship structure", Marine Structures, 20(3), pp.143~163 (2007)
- Radaj, D., "Welding residual stresses and distortion: calculation and measurement" (2003), DVS-Verlag
- Radaj, D., "Fatigue assessment of welded joints by local approaches" (2006), Woodhead Publishing
- Influence of compressive mean stresses on the fatigue strength of welded ship structures (in German), "Rörup, J.", TU Hamburg-Harburg, ~, pp.Report 619 (2003)
- Rosenthal, D., "Mathematical theory of heat distribution during welding and cutting", Transactions ASME Supplement, 20(5), pp.220s~234s (1941)
- Ruyter, E., "Development and assessment of welding procedures for avoiding weld joint cracking in highly restrained offshore steel structures", 박사, pp.1993
- Rykalin, N., "Die Wärmegrundlagen des Schweißvorganges (Thermal fundamentals of the welding process)" (1952), Verlag Technik
- VSM, "Production standard of the german shipbuilding industry", Verband für Schiffbau und Meerestechnik e.V, ~ (2006)
- Wichers, M., "Welding under uniaxial cyclic loading - experimental and numerical investigations (in German)", 박사, pp.2006
- Zacke, S., "Advances in Marine Structures" (2011), Taylor & Francis Group