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Lindström, P. (2015). Improved CWM platform for modelling welding procedures and their effects on structural behaviour. (Doctoral dissertation). Trollhättan: University West
Open this publication in new window or tab >>Improved CWM platform for modelling welding procedures and their effects on structural behaviour
2015 (English)Doctoral thesis, monograph (Other academic)
Abstract [en]

A welding procedure specification is the document describing how a weld joint should be constructed. Arc weld processes are characterized by transient thermal behavior, leading to rapid changes in material properties and dynamic interaction between weld and base material. The objective of the project is to explore how the use of an improved CWM-platform affects representative stress and strain fields in order to assess welding procedure qualification records. Forthis project, the accumulated thermal and mechanical influences from the first run to the final run are brought forward, in one and the same meshed geometrical model. Both the thermal and mechanical material model of the platform are designed to be used for modelling of the base- and weld material,promoting the simulation of the intricate combination of the thermal, elastic,and plastic strains on the plastic strain hardening and the formation of residual stress fields. The output of the simulation is mainly weld cooling times, residual stresses, and deformations. This analysis is taken further by examining how residual stresses influence crack driving force under elastic and plastic loading. In addition, the output from the simulations can be used to assess the realism of the proposed welding parameters. The main experimental welding procedure examined comes from the IIW RSDP Round Robin Phase II benchmark project, where the main aim was to benchmark residual stress simulations. This work was found to contain many applicable challenges of a CWM-analysis project.

Place, publisher, year, edition, pages
Trollhättan: University West, 2015. p. 202
Keywords
CWM, FEM, WELD, STRESS, EPFM
National Category
Manufacturing, Surface and Joining Technology
Research subject
ENGINEERING, Manufacturing and materials engineering
Identifiers
urn:nbn:se:lnu:diva-61961 (URN)978-91-87531-08-8 (ISBN)978-91-87531-07-1 (ISBN)
Public defence
2015-09-15, C118, Högskolan Väst, Trollhättan, 10:15 (English)
Opponent
Supervisors
Available from: 2017-03-30 Created: 2017-03-30 Last updated: 2017-03-30Bibliographically approved
Lindström, P., Caprace, J.-D., Mishra, B., Pires, F., Roland, F., Schipperen, I., . . . Kim, M. H. (2015). Materials and Fabrication Technology: Committee v.3 (1ed.). In: Carlos Guedes Soares & Yordan Garbatov (Ed.), Proceedings of the 19th International Ship and Offshore Structures Congress, Volume 2: Committee v.3 Materials and Fabrication Technology (pp. 619-698). EH Leiden, Nederlands: CRC Press, 2, Article ID V.3.
Open this publication in new window or tab >>Materials and Fabrication Technology: Committee v.3
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2015 (English)In: Proceedings of the 19th International Ship and Offshore Structures Congress, Volume 2: Committee v.3 Materials and Fabrication Technology / [ed] Carlos Guedes Soares & Yordan Garbatov, EH Leiden, Nederlands: CRC Press, 2015, 1, Vol. 2, p. 619-698, article id V.3Chapter in book (Other academic)
Abstract [en]

Due to the past crises, the shipbuilding and offshore industry has realised that new innovative designs and design and production methods are necessary to decrease operational costs, production costs and emissions,while meeting the changing rules and regulations. This ISSC-V.3 report is discussing recent developmentin materials and fabrication technology applied to ship and offshore structures.Chapter 2 focuses on worldwide trends in materials and fabrication methods. Developments in metallicand non-metallic structural materials are dealt in Chapter 3. Advances in fabrication and joining technologiessuch as welding are increasing. Some main areas of applications and research in those areas aredescribed in Chapter 4. Innovative development about corrosion protection systems are presented inChapter 5 while Chapter 6 give an overview about the application of production simulation and virtualreality to improve the production management of ship and offshore structures.The ISSC-V.3 technical committee has performed a benchmark to define a Best Practice Guideline touse Computational Welding Mechanics tools (CWM) in shipbuilding and offshore industry. To achievethis objective various experimental welding tests have been performed in order to give a reference point.Both the residual welding distortions and residual stresses have been compared between numerical simulationsand welding experiments for a common “T” welded assembly used in the shipbuilding industry.However, it has been decided to publish the results of this study in a separate document. Nevertheless, Chapter 7 of this report presents the state of the art as well as the experimental test case that has been analysed.

Place, publisher, year, edition, pages
EH Leiden, Nederlands: CRC Press, 2015 Edition: 1
Keywords
Lightweight, composites, bonding, welding, residual stress, distortions, line heating, fatigue, productivity, corrosion, discrete event simulation, virtual and augmented reality.
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:lnu:diva-62001 (URN)978-1-138-02897-5 (ISBN)978-1-138-02896-8 (ISBN)
Projects
Funktionsstabilitet
Available from: 2017-03-30 Created: 2017-03-30 Last updated: 2017-04-05Bibliographically approved
Lindström, P., Jonsson, A., Jernberg, A. & Östby, E. (2015). Non-linear fracture mechanics in LS-DYNA and LS-PrePost. In: European LS-DYNA Conference 2015: Conference Papers. Paper presented at 10th European LS-DYNA Conference 15-17 June, 2015, Würzburg, Germany. Würzburg: DYNAmore GmbH
Open this publication in new window or tab >>Non-linear fracture mechanics in LS-DYNA and LS-PrePost
2015 (English)In: European LS-DYNA Conference 2015: Conference Papers, Würzburg: DYNAmore GmbH , 2015Conference paper, Published paper (Other academic)
Abstract [en]

Fracture mechanics provides an engineering framework for assessing the consequences of defects instructures. In linear elastic fracture mechanics (LEFM), stress intensity factors KI, KII and KIII are usedfor characterizing the stress singularity at the crack tip, which arises from the theory of linear elasticity.Crack growth is assumed to occur when KI exceeds the fracture toughness KC. LEFM can be usefulfor brittle materials, or when the size of the plastic zone is small compared to global dimensions. In non-linear fracture mechanics (EPFM), an energy based criterion is used for assessing the risk forcrack growth: if the energy release rate at the crack tip exceeds what is required for creating newsurfaces in the material, crack growth will occur. Under certain assumptions the energy release rate atthe crack tip can be calculated by a path independent integral, the so-called J-integral. In modernFE-based fracture mechanics applied to practical design, the structure under consideration ismodelled, including cracks at specific locations, and the J-integral values are computed and used asdesign criteria. From a numerics viewpoint, the J-integral has many appealing properties: it can beevaluated from the far-field solution, which reduces numerical errors that may arise close to the cracktip, and the expected path-independence can to some extent be used as a quick check on solutionvalidity.Evaluation of the J-integral from LS-DYNA simulation results has been implemented as a postprocessingtool in LS-PrePost, including consistent treatment of residual stresses. The implementationcovers both 2D (plane stress / plane strain) and 3D applications, using the virtual crack-tip extension(VCE) method. The tool is accessible both via the LS-PrePost GUI and via command file interface.

Place, publisher, year, edition, pages
Würzburg: DYNAmore GmbH, 2015
Keywords
EPFM, Elastic Plastic Fracture Mechanics, Nonlinear Fracture Mechanics, CDF, Crack Driving Force, J-integral
National Category
Metallurgy and Metallic Materials Applied Mechanics
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62000 (URN)
Conference
10th European LS-DYNA Conference 15-17 June, 2015, Würzburg, Germany
Available from: 2017-03-30 Created: 2017-03-30 Last updated: 2017-04-24Bibliographically approved
Lindström, P. (2013). DNV Platform of Computational Welding Mechanics. Hövik, Norge: Det Norske Veritas AS
Open this publication in new window or tab >>DNV Platform of Computational Welding Mechanics
2013 (English)Report (Other academic)
Abstract [en]

This document presents the DNV Platform of Computational Welding Mechanics, CWM, with its associated CWM-methodology. That has been developed, validated and implemented as a part of DNV’s Technology Leadership program in the field of Structural Integrity and Materials Technology.A successful CWM implementation requires that the actual organisation has gained the knowledge and understanding of the following related topics:- Welding Engineering with an emphasis on the welding process and its thermodynamics- Weld process quality control such as calibration, validation as well as DAQ, (Data Acquisition)- Transient thermo-mechanical coupled FE-analyses and constitutive modelling- Computational platforms comprising the selection of hardware, operative system and FEM-code as well as suitable pre- and post-processing toolsFrom that perspective there is a lack of reliable and/or hands-on oriented CWM Engineering Handbooks and best recommended practices available on the market. For that sake is the DNV CWM-methodology and its hands on solutions presented.The CWM-methodology described can not only be used for residual stress assessments, as presented in this report. It can also be used for various applications such as assessment of used and/or proposed WPS, Welding Procedure Specifications as well as optimisation of the manufacturing and production process of integrated metallic structures.From the results of a parametric CWM-study have three (3) factors been identified to drive and/or contribute to the magnitude of the weld residual stresses in ship steel plate materials. The contributing and/or driving factors identified are the:- Thermal- and Mechanical Boundary Conditions during the production welding- Yield stress difference between the base- and the weld filler material- Weld heat input, Q, which affects the weld cooling time

Place, publisher, year, edition, pages
Hövik, Norge: Det Norske Veritas AS, 2013. p. 50
Series
DNV REPORT ; 2014-2356
Keywords
Funktionsstabilitet, IIW, CWM, Computational Welding Mechanics, Weld Residual stresses, WPS Assessment, Weld Simulations, Distortions Kinematic Hardening
National Category
Manufacturing, Surface and Joining Technology
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-61971 (URN)
Available from: 2017-03-30 Created: 2017-03-30 Last updated: 2017-04-11Bibliographically approved
Lindström, P. & de Blanche, A. (2013). Integration and Optimization of a 64-core HPC for FEM- and/or CFD Welding Simulations. In: Roger Oswald (Ed.), NAFEMS NORDIC Seminar: Improving SimulationPrediction by Using Advanced Material Models. Paper presented at NAFEMS NORDIC Seminar: Improving Simulation Prediction by Using Advanced Material Models, November 5 – 6, 2013 Lund, Sweden. München: NAFEMS Deutschland, Österreich, Schweiz - DACH
Open this publication in new window or tab >>Integration and Optimization of a 64-core HPC for FEM- and/or CFD Welding Simulations
2013 (Swedish)In: NAFEMS NORDIC Seminar: Improving SimulationPrediction by Using Advanced Material Models / [ed] Roger Oswald, München: NAFEMS Deutschland, Österreich, Schweiz - DACH , 2013Conference paper, Oral presentation with published abstract (Other academic)
Place, publisher, year, edition, pages
München: NAFEMS Deutschland, Österreich, Schweiz - DACH, 2013
Keywords
HPC, Linux, MPI, SMP, FEA, FORTRAN, FEM, CWM
National Category
Computer Engineering
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62073 (URN)
Conference
NAFEMS NORDIC Seminar: Improving Simulation Prediction by Using Advanced Material Models, November 5 – 6, 2013 Lund, Sweden
Projects
Funktionsstabilitet
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2018-01-13Bibliographically approved
Lindström, P. & Josefson, L. (2012). 2D, Axisymmetric and 3D Finite Element Analysis Assessment of the IIW RSDP Round Robin Initiative, Phase 1 and Phase 2. Denver, Colorado, USA: International Institute of Welding
Open this publication in new window or tab >>2D, Axisymmetric and 3D Finite Element Analysis Assessment of the IIW RSDP Round Robin Initiative, Phase 1 and Phase 2
2012 (English)Report (Other academic)
Abstract [en]

A further assessment of the IIW numerical and experimental test RSDP Round Robin Initiative, Phase 1 and Phase 2 is presented. Focus is on the weld process specification, and the importance ofuse of as realistic as possible weld process parameters in the weld simulations. Considerable interpretation is often required of the weld designer and of the FE modeller when simulatinga weld process. The paper demonstrates, on the IIW RSDP round Robin benchmarks, that with interpretation and judgement, Computational Welding Mechanics using a variety of models and approaches is possible. Difficulties in interpretation could be substantially reduced through the use of industrial methods of specification, weld process specifications (WPS). For this reason, the authors recommend that all benchmarks follow the standards and definitions used in internationally recognised industrial standards. For the Phase 1 benchmark three-pass butt welded pipe case, which was a designed case for weld simulations, rotationally symmetric and fully 3D results are presented for temperatures, deformations and stresses. These results are compared with IIW benchmark results, and differences caused by weld process parameters and material modelling (for the mechanical analysis) are discussed.For the Phase 2 benchmark two pass butt welded coupon plate case, experimental results are available. The incomplete documentation from the weld experiment compared to realistic WPS is discussed. 3D thermal results coupled with generalised plane strain 2D results for temperatures, deformations and stresses using correct WPS and realistic material data are presented and compared with IIW benchmark results. SFor both Benchmarks the LS-Dyna FE software was used, with a major modification being a modified Goldak heat source model.

Place, publisher, year, edition, pages
Denver, Colorado, USA: International Institute of Welding, 2012. p. 23
Series
IIW Annual Assembly 2012, WG X-XIII-XV ; X-1712-12
Keywords
IIW, RSDP, Round Robin Initiative, Phase 1 and Phase 2
National Category
Applied Mechanics
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62069 (URN)
Projects
Funktionsstabilitet
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2018-02-14Bibliographically approved
Lindström, P. (2012). Arctic Technology: Report of Committe V.6 (1ed.). In: W. Fricke & R. Bronsart (Ed.), Proceedings of the 18th International Ship and Offshore Structures Congress, Volume 2: Report of Committe V.6 - Arctic Technology: (pp. 243-274). Hamburg: Schiffbautechnische Gesellschaft
Open this publication in new window or tab >>Arctic Technology: Report of Committe V.6
2012 (English)In: Proceedings of the 18th International Ship and Offshore Structures Congress, Volume 2: Report of Committe V.6 - Arctic Technology / [ed] W. Fricke & R. Bronsart, Hamburg: Schiffbautechnische Gesellschaft , 2012, 1, p. 243-274Chapter in book (Other academic)
Place, publisher, year, edition, pages
Hamburg: Schiffbautechnische Gesellschaft, 2012 Edition: 1
Keywords
Arctic structures, ice loads, ice class, rules, arctic environment
National Category
Vehicle Engineering
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62015 (URN)978-3-87700-132-5 (ISBN)
Available from: 2017-03-31 Created: 2017-03-31 Last updated: 2017-04-05Bibliographically approved
Lindström, P., Josefson, L., Schill, M. & Borrvall, M. (2012). Constitutive Modelling and Finite Element Simulation of Multi Pass Girth Welds. In: Roger Oswald (Ed.), NAFEMS NORDIC Conference: Engineering Simulation: Best Practices, New Developments, Future Trends. Paper presented at NAFEMS NORDIC Conference: Engineering Simulation: Best Practices, New Developments, Future Trends ; May 22 - 23, 2012 Gothenburg, Sweden. München, Germany: NAFEMS Deutschland, Österreich, Schweiz - DACH
Open this publication in new window or tab >>Constitutive Modelling and Finite Element Simulation of Multi Pass Girth Welds
2012 (English)In: NAFEMS NORDIC Conference: Engineering Simulation: Best Practices, New Developments, Future Trends / [ed] Roger Oswald, München, Germany: NAFEMS Deutschland, Österreich, Schweiz - DACH , 2012Conference paper, Oral presentation with published abstract (Other academic)
Place, publisher, year, edition, pages
München, Germany: NAFEMS Deutschland, Österreich, Schweiz - DACH, 2012
Keywords
CWM, FEA, FEM
National Category
Applied Mechanics
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62071 (URN)
Conference
NAFEMS NORDIC Conference: Engineering Simulation: Best Practices, New Developments, Future Trends ; May 22 - 23, 2012 Gothenburg, Sweden
Projects
Funktionsstabilitet
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2017-04-05Bibliographically approved
Josefson, L., Lindström, P. & Molin, M. (2010). 2D and 3D Simulation of the IIW Round Robin Benchmark. Istanbul, Turkey: International Institute of Welding
Open this publication in new window or tab >>2D and 3D Simulation of the IIW Round Robin Benchmark
2010 (English)Report (Other academic)
Place, publisher, year, edition, pages
Istanbul, Turkey: International Institute of Welding, 2010. p. 29
Series
IIW Annual Assembly 2010, WG X-XIII-XV ; XIII-2325
Keywords
Funktionsstabilitet, IIW, CWM, Computational Welding Mechanics, RSDP
National Category
Applied Mechanics
Research subject
Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62049 (URN)
Projects
Funktionsstabilitet
Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2017-04-11Bibliographically approved
Soares, C. G., Basu, R., Cerup Simonsen, B., Egorov, G. V., Hung, C. F., Lindström, P., . . . Yoshikawa, T. (2009). Damage Assessment After Accidental Events: Report of Committee V.1 (1ed.). In: C.D. Jang & S.Y. Hong (Ed.), Proceedings of the 17th International Ship and Offshore Structures Congress: Volume 2 (pp. 1-72). Seoul, Korea: Seoul National University
Open this publication in new window or tab >>Damage Assessment After Accidental Events: Report of Committee V.1
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2009 (English)In: Proceedings of the 17th International Ship and Offshore Structures Congress: Volume 2 / [ed] C.D. Jang & S.Y. Hong, Seoul, Korea: Seoul National University , 2009, 1, p. 1-72Chapter in book (Other academic)
Abstract [en]

This paper contains the report of the Committee, which is a new one that was created todeal with the methods to assess damage and residual strength after accidental events.The name of the committee, being a short one may give a wrong impression about itsscope as it mentions damage assessment while the mandate refers that there should beconcern for the extent of damage and local and global residual strength of shipstructures, after accidental events. Therefore the contents of the report deal also withmethods to determine local and global residual strength, including the specification ofthe appropriate loads.It starts by providing a description of the type of damages that can be found in thevarious accidental events. Representative scenarios are described and the typicaldamages that results from the specific accidents are indicated. Next section describeshow in real situations the damaged state is perceived. Thus, inspection methods aredescribed as well as the available approaches to derive information about the status ofthe structure from indirect measurements.Loads on the structure are treated afterwards, including the loads that are generatedduring the accidental situation itself and also after the accident when the ship is indamaged state, often listed and with non symmetric sections. The loads are used todetermine ship strength using the assessment methods described in section 5, whichdeals with various types of components.If the ship is considered not having enough strength for temporary voyage to repairyard local repairs are necessary. Otherwise she will travel to a repair shipyard and berepaired there. The various types of problems raised in repair are dealt with in thefollowing section.Finally last section deals with salvage and recovery strategies which are necessary inthe cases of very large damage in ships.

Place, publisher, year, edition, pages
Seoul, Korea: Seoul National University, 2009 Edition: 1
Keywords
Residual Strength, Accidental Damages, Collision, Grounding, Fire, Explosions, Recovery, Salvage, In-Service Repair, Emergency Repairs
National Category
Vehicle Engineering
Research subject
Shipping, Maritime Science; Shipping, Maritime Science
Identifiers
urn:nbn:se:lnu:diva-62016 (URN)
Projects
Funktionsstabilitet
Available from: 2017-03-31 Created: 2017-03-31 Last updated: 2017-04-11Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4871-4470 

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