In order to achieve integrated condition in the girth welding of high pressure natural gas transmission pipelines, the weld zones and its surrounding area should have good mechanical properties. Residual stresses are an important defect especially in the girth welding of the pipeline. In this study, two API X70 steel pipes (with spiral seam weld) of 56 inches outside diameter and 0.780 inch wal...

in this research, a novel method to decrease micro-residual stresses of fibrous composites by adding carbon nanotubes (cnts) is proposed in detail. the negative coefficient of thermal expansion and the high young’s modulus of cnts can be utilized to counterbalance the process induced residual stresses in composites. to this end, first, the effects of adding cnts to the matrix of fibrous composi...

final step of rail manufacturing is cold rolling straightening process and it hassignificant effects on mechanical properties, straightness, flatness and development of residualstresses. measurement of residual stresses after straightening process is obligated by railmanufacturing standards. in the present investigation, an attempt has been made to evaluateresidual stresses after straightening ...

the residual stresses in composite laminates depend on several factors including the conditions of fabricating process, property of materials, direction and lay-ups of the layers. however the thermo-elastic behavior of composite is one of the most important parameters affecting the magnitude of residual stresses. the elastic properties and residual stresses do not remain constant under cyclic t...

Final step of rail manufacturing is cold rolling straightening process and it hassignificant effects on mechanical properties, straightness, flatness and development of residualstresses. Measurement of residual stresses after straightening process is obligated by railmanufacturing standards. In the present investigation, an attempt has been made to evaluateresidual stresses after straightening ...