EFFECTS OF SURFACE DEFECTS ON THE STATIC STRENGTH OF WELDS IN SPIRAL-SEAM TUBES

摘要

1. A theoretical analysis has been performed on the effects of surface defects on the static strength of spiral-welded tubes under conditions of biaxial loading. Analytic expressions have been derived for the critical circumferential stress, which incorporate the effects of surface defects and contact hardening in the soft sublayer. A formula has been derived for the critical pressure in a spiral-weld tube that incorporates the depth of a surface defect. 2. Comparison of viability for straight-weld and spiral-weld tubes under working conditions has shown that straight-weld tubes are preferable.