The finite element model WeldsimS has been developed that quantifies residual stresses in welded steel structures. Input to the model is the structure geometry, material properties, and welding procedure; the output includes the development of temperature, stress, and strain fields during the welding operation. The residual stress field is then made available for a failure assessment analysis.
All main mechanisms causing residual stresses in steel are included in WeldsimS:
Transformations between different solid phases (austenite, ferrite, bainite,…) and their dependence on thermal history.
Phase dependent densities and thermal expansions.
Flow stress that depends on temperature and viscoplastic strain rate and deformation.
Some WeldsimS features:
Differences in properties between weld metal and base metal are taken into accounted.
Weld metal elements are “activated” when they are approached by weld heat source.
The build-up of fillet regions in multi-pass welding is simulated by pre-defining weld metal elements that are activated during each pass.
Weld joint bonding is obtained by changing the interface boundary conditions after reaching a threshold surface temperature.
Adaptive mesh refinement for numerical accuracy and spatial resolution of the stress field.
Export of stress field to failure assessment analyses in 3D domains or 2D cross sections.
Temperature field during deposition of weld metal in the groove.
Residual hoop stress for 2 different levels of local mesh refinement.