Method for Mitigating Residual Weld Stresses
The presence of residual stresses in weldments can adversely and prematurely cause the breakage or failure of a work piece. The present invention presents a method of reducing the residual stress found at welded joints. Residual stress created from thermal contraction at joints is reduced by compensating for the resultant stress through thermally compressing or shrinking a section of the metal work piece prior to welding. Shrinking the joint members before welding provides the source of the compressive stress used to mitigate the residual tensile stress from welding.Benefits
Stretching and upsetting of the weld metal is the primary mechanism for relieving the tensile forces in most weldments. The combination of stresses in highly restrained joints, however, restricts the material flow. Less of the shearing component of stress is available for joint deformation. The current invention mitigates one component of residual stress by compensating a compressive force into the weldment.
There are no techniques available that relieve welding stresses concurrent with production welding. The invention can be used to mitigate residual stresses in highly restrained welded joints. Joints include moment-frame, and other complete penetration structural welds between members and trusses with restrained ends.
Stage of Development
A provisional patent application has been filed with the U.S. Patent and Trademark Office.
This technology has been demonstrated to work in proof-of-concept experiments. It is available for developmental research support/licensing under either exclusive or non-exclusive terms.
Additional Info
http://www.civil.utah.edu/faculty/reaveley/index.htm
Inventor(s): William Komlos, Lawrence Reaveley
Type of Offer: Licensing
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