Effect of one and two stiffeners on residual stresses of ship hull

Failure of ship hulls may be a result of a combination of factors. Residual stress caused by welding of the stiffeners on to the steel plates is one of the contributing factors to the failure. This analysis was completed for a more in-depth look at the residual stress distribution found at a typical weld-stiffener connection of ship hulls. Three specimens were built to represent small segments of an actual ship hull. The sizing of the specimens was designed so they could be accommodated at the test facility available at the Canadian Neutron Beam Centre in the Chalk River Laboratories. The specimens were made out of 9.53 mm thick plate of 350 WT grade structural steel stiffened by L127x76.2x9.53 stiffeners. The non-destructive neutron diffraction method was used to collect strain data at locations within the volume of the specimens. The method of neutron diffraction uses the crystal lattice of the sample material as an internal strain gauge. The test results were analyzed to determine the distribution of the residual stress in the parent steel plate and the effect the welding of the stiffeners has on the residual stress field. This thesis presents the three-dimensional residual stress for the parent plate and specimens with one and two stiffeners obtained from this study.