Strain Based Design—What the Contribution of a Pipe Manufacturer Can Be

Exploration of new energy resources located in areas of complex ground and ambient climate imposes strict requirements on pipeline material and design. One of the major research issues in such areas is differential ground movement, which, possibly, is associated with large longitudinal straining in addition to plastic circumferential elongation. Hence, common design principles need thorough re-consideration, notably with respect to strain hardening properties of both base metal and girth welds. This paper summarizes results of a research, which was conducted within Europipe GmbH and supported by Salzgitter Mannesmann Forschung GmbH. Central to the discussion is the numerical representation of strain hardening behavior of pipeline steels, which mainly was focused on base metal. In particular, the discussion comprises stress-strain behavior in transverse as well as in longitudinal direction, the effect of material ageing and the significance of uniform elongation.