PSI - Issue 19

Lloyd Hackel et al. / Procedia Structural Integrity 19 (2019) 346–361 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

9

354

2” x 2”

FEA input

Block-peened and RS measured

Cask FEA model

11”

Stress correction cask to coupon

FEA model coupon

Corrected RS in cask

RS measured in Peened panel

Figure 8. Methodology for computing residual stress in a canister compared to that measured in test panel starts with stress generated by laser peening and measuring a 2 inch (50 mm) square block. Results used as calibration input into canister FEA model. Canister panel virtually peened and stress calculated in a panel section of a canister. Section of canister is “virtually” separated and allowed to strain. R educed stress in free panel calculated and compared to that measured in canister. Stress reduction in-canister vs free sample is calculated.

Figure 9. FEA analysis shows that stress in a canister is deeper than measured in free panel. In current case stress depth in a canister is 5.5 mm,that is 2 mm deeper than measured in a free panel.

Stress in the canister is computed and then stress in a model of an unconstrained panel calculated allowing calculation of the increased stress retained in the canister. Figure 9 shows an example calculation where the stress retained in the canister is approximately 2 mm deeper than that measured in the panel.