Influence of anisotropy on flaw acceptability in spiral welded pipe sections

The structural response of spiral welded pipes in strain based design related projects has gained interest. The spiral weld is a potential weak link, whose structural response is influenced by directional material anisotropy introduced during the production of skelp and pipe. In this paper, Hill’s 1948 yield criterion is used to investigate the response of curved wide plate sections taken from a spiral pipe under plastic tensile deformation by means of numerical analysis. It is concluded that conducting finite element calculations of spiral welded pipes sections can yield unconservative designs, when neglecting anisotropic plastic material response