2 research outputs found
Recommended from our members
ProfilometryâBased Indentation Plastometry and Uniaxial Testing of Pipelines: Detection of InâPlane Anisotropy and Potential for Simplification of Test Procedures
This article concerns anisotropy in stressâstrain relationships exhibited by steel pipelines. Since the stress from internal pressurization is highest in the hoop direction, standard industrial practice to measure these properties has focussed on tensile testing in this direction, requiring a prior flattening operation. The associated plastic deformation may affect properties, typically causing a (poorlyâdefined) degree of hardening and the creation of inhomogeneity. Field testing of such pipelines, requiring inâsitu measurement of tensile properties (yield stress (YS) and ultimate tensile stress (UTS)), is based on indentation testing of the outer surface. One such test (profilometryâbased indentation plastometry (PIP)), not only gives the stressâstrain curve, but also allows detection of any (inâplane) anisotropy, with a high sensitivity. Both PIP testing and compression testing (with and without prior flattening) have confirmed that none of the eight pipes examined in the current work exhibited any such anisotropy, although the effects of flattening did tend to generate apparent anisotropy in the tensile test outcomes. It may therefore be appropriate to switch the focus of tensile testing to the axial direction, such that no flattening would be required.</jats:p
Recommended from our members
ProfilometryâBased Indentation Plastometry and Uniaxial Testing of Pipelines: Detection of InâPlane Anisotropy and Potential for Simplification of Test Procedures
Publication status: PublishedThis article concerns anisotropy in stressâstrain relationships exhibited by steel pipelines. Since the stress from internal pressurization is highest in the hoop direction, standard industrial practice to measure these properties has focussed on tensile testing in this direction, requiring a prior flattening operation. The associated plastic deformation may affect properties, typically causing a (poorlyâdefined) degree of hardening and the creation of inhomogeneity. Field testing of such pipelines, requiring inâsitu measurement of tensile properties (yield stress (YS) and ultimate tensile stress (UTS)), is based on indentation testing of the outer surface. One such test (profilometryâbased indentation plastometry (PIP)), not only gives the stressâstrain curve, but also allows detection of any (inâplane) anisotropy, with a high sensitivity. Both PIP testing and compression testing (with and without prior flattening) have confirmed that none of the eight pipes examined in the current work exhibited any such anisotropy, although the effects of flattening did tend to generate apparent anisotropy in the tensile test outcomes. It may therefore be appropriate to switch the focus of tensile testing to the axial direction, such that no flattening would be required.</jats:p