Dragilyev A. Determination of residual stresses and eatimation of their influence on the longevity of circumferential of pipelines in zone welding joints.

. Research object; welding joints with cracks under cyclic loads. Reaseach methods: develops calculation-experimental method of determination residual stresses in zone of multi-layer circumferential welding beads of pipelines and estimation of their influences on the durabelity of welding joints with cracks under cyclic loads. Theoretical and practical results: within the shell theory , a mathematic model for determining components of stress state with taking into account the two-dimensional plas-tic deformation distribution localized near the welding bead and structural phases changes in the thermal influence zone is cre-ated.Novelty: in first having used crack clouser mathematical model and the concept of effectlve amplitude of stress intensity factor a calculation model for taking into account the influence of residual stresses on fatique fracture under cyclic loads is ob-tained. The extend of introduction: the developed method has