PSI - Issue 41

Chouaib Zeghida et al. / Procedia Structural Integrity 41 (2022) 384–393 Zeghida Chouaib et al. / Structural Integrity Procedia 00 (2022) 000–000

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Fig. 10. Observed effect of the applied total stress on the contribution of IHSI.

5.3. Effect of Changing Residual Stresses during Mid-life If a change in residual stress is desired in mid-life, it can only be changed to axisymmetric self-equilibrating through the wall. Figure 11 present results for the cases where residual stresses were changed by IHSI treatment to obtain linearly varying, axisymmetric residual stresses in the weld region. The distribution of these residual stresses in PRAISE code is defined by specifying the mean and standard deviation of the stresses on the ID of the pipe. The recommended post-IHSI stress distribution based on the data analyzed in this paper a mean of -276 MPa has a large effect on reducing the leak probabilities following the IHSI treatment.

Fig. 11. Effect of Reducing Residual Stress at Mid-life (20 Years) with IHSI process