Virtual Welded-Joint Design Integrating Advanced Materials and Processing Technologies

Technical Report · Fri Apr 15 04:00:00 EDT 2005

DOI:https://doi.org/10.2172/940295· OSTI ID:940295

Yang, Z; Dong, P; Liu, S; Babu, S; Olson, G; DebRoy, T

The primary goal of this project is to increase the fatigue life of a welded-joint by 10 times and to reduce energy use by 25% through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of a welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve high fatigue strength in a welded-joint it is necessary to manage the weld bead shape for lower stress concentration, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the optimization of the welding process, the welding consumable, the base material, as well as the structure design. The concept of virtual welded-joint design has been proposed and established in this project. The goal of virtual welded-joint design is to develop a thorough procedure to predict the relationship of welding process, microstructure, property, residual stress, and the ultimate weld fatigue strength by a systematic modeling approach. The systematic approach combines five sub-models: weld thermal-fluid model, weld microstructure model, weld material property model, weld residual stress model, and weld fatigue model. The systematic approach is thus based on interdisciplinary applied sciences including heat transfer, computational fluid dynamics, materials science, engineering mechanics, and material fracture mechanics. The sub-models are based on existing models with further development. The results from modeling have been validated with critical experiments. The systematic modeling approach has been used to design high fatigue resistant welds considering the combined effects of weld bead geometry, residual stress, microstructure, and material property. In particular, a special welding wire has been developed in this project to introduce compressive residual stress at weld toe for weld fatigue resistance.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 940295
• Report Number(s): ORNL02-0633
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPUTERIZED SIMULATION
DESIGN
DISTRIBUTION
FLUID MECHANICS
FRACTURE MECHANICS
GEOMETRY
HEAT TRANSFER
MICROSTRUCTURE
OPTIMIZATION
PERFORMANCE
PROCESSING
PRODUCTIVITY
STEELS
WELDING