Browsing by Author "Wescott, A."

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    Characterisation of residual stress state and distortion in welded plates stress engineered by local mechanical tensioning
    (Transtec Publications; 1999, 2014-01-01T00:00:00Z) Ganguly, Supriyo; Wescott, A.; Nagy, T.; Colegrove, Paul A.; Williams, Stewart W.
    Local mechanical tensioning is one of the most efficient and industrially relevant stress engineering techniques to modify weld residual stress field and subsequently reduce buckling distortion. However, application of rolling load and its magnitude need to be optimised for an energy efficient rolling process. In the present study gas metal arc butt welded plates of low carbon mild steel were rolled by a dual roller in different rolling configuration (top and reverse side rolling) and with different magnitude of rolling load. All the plates were rolled post welding. Residual strain profiles of the post weld rolled plates were measured, using the SALSA strain scanner, and the inplane stress were characterized. Average distortion of the rolled plates was correlated with the residual stress state. Reverse rolling was found to be more effective in removing distortion while the stress profile did not show any significant reduction of the peak stress.
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    Rolling to control residual stress and distortion in friction stir welds
    (2010-08-31T00:00:00Z) Wen, S. W.; Colegrove, Paul A.; Williams, Stewart W.; Morgan, S. A.; Wescott, A.; Poad, M.
    Considerable residual stress and distortion can be produced by friction stir welding, impeding industrial implementation. Finite element analysis has been used to develop three innovative rolling methods that reduce residual stress and distortion in friction stir welds. Of the three methods, post-weld direct rolling where a single roller is applied to roll the top surface of the weld after the weld metal has cooled to room temperature proved the most effective. The residual stress predictions from the model compared favourably with residual stress measurements reported in an accompanying paper. Finally, the effectiveness of using post-weld direct rolling is illustrated with an industrial example of a large integrally stiffened panel, where the distortion was virtually eliminated.