In this study, an experimental method has been studied to measure the residual stresses
on a specimen with I-groove weldment. The specimens were extracted from I-groove weldment
which was joined by SAW (Submerged Arc Welding) with CO2 shield gas. A FEA (Finite Element
Analysis) model was developed for the estimation of the residual stresses for the specimen.
Measurements were carried out using ESPI(Electronic Speckle Pattern Interferometry) system
which can measure the strain distribution on the surface of specimen. The residual stresses were
estimated by the value of strain measured by ESPI system. Strain gages were added to evaluate the
accuracy of ESPI system. In addition, a three-dimensional FE model was used to estimate the
residual stresses generated by the welding procedure. A thermal elasto-plastic analysis was
performed by the FEA. The stresses measured by the experiments were compared with the results of
FEA. Also, discussed are the difference and agreement between the stresses obtained by
experiments and FEA, respectively.