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Integrated Design and Manufacturing of Welded Structures

  • Publisert 25.02.2007
  • Sist oppdatert 30.05.2011

Frontpage report

The more than 20 research partners have, based on findings on earlier Nordic projects, worked together to improve the design, fabrication and cost effectiveness of advanced welded structures. The results of the project will provide practical guidance of immediate value to industry and exploitation will concentrate on the provision of information in a userfriendly form that is readily applicable.

Smaller portions of the result are of a medium term nature which will lead toward implementation in 3-5 years. Although the project has primarily addressed transportation, work vehicle, and energy related structures, there is no doubt that the results will be applicable to other industries involved with fatigue-loaded welded structures. 

The following major results have been achieved within the project:

Increased understanding

  • Significant improvement has been achieved in the performance and understanding of fatigue life assessment of welded structures
  • A draft of a weld quality classification system for fatigue loaded structures based on a modern scientific foundation is under development
  • Spatter induced cold laps is still the most frequent defect in MAG-welding and work has been done to identify the process parameters which lead to this defect type
  • Automated assessment of weld geometry and the determination of weld quality can be unsafe in cases of the presence defects, especially cold laps defects
Predictive tools
  • A simulation tool for testing the effect of variations and changes in welding parameters is under development and has been applied on simple weld geometries
  • FE simulations of welding induced stresses are still quite demanding to computational capacity, but this project shows that many process related influences on residual welding induced stresses, and thereby fatigue resistance, can be investigated with moderate model size and calculation
Improved weld quality
  • Two important methods of weld improvement have been investigated, i.e., grinding according to IIW and UIT (Ultrasonic Impact Treatment)
  • Fatigue test of gas cut edges in thick sections showed fatigue limit higher than current design curves
  • In the case of improved welds, the failure location may shift to the root side so design methods must also have the capacity to assess these potential failures
  • Modern cutting methods for thick sections showed higher fatigue strengths that what is allowed in current design rules

Project duration: 2003 - 2007