The Welding Institute, Cambridge,
Pages: 11 Published: Jan 1988
An investigation of the effects of proof loading on residual stresses in test panels simulating welds in ammonia storage spheres was performed. The two test panels contained welds with different degrees of misalignment and distortion. Measurements were made of the surface residual stresses before and after loading to about two thirds yield and of the strain changes during loading. Previous research has suggested that the residual stress after proof loading is a function of material yield strength and applied proof stress only. In the present project, it was found that the relaxation of residual stresses transverse to the weld was sensitive to the local geometry. However, a simple method for including the effects of residual stresses in defect assessments is proposed.
residual stresses, proof loads, mechanical relaxation, pressure vessels, misalignment, defect assessment, stress concentration factors
Paper ID: STP26359S