Testing of pipe sections

Abstract

A device and the basic technology has been developed for tensile testing pipe sections samples (tensile testing PSS) for quantitative estimating ultimate tensile and yield stresses in ring samples (PSS samples) cut from pipes. This tensile testing device provides the opportunity for compensating frictional forces during the tensile test, and using exchangeable bearings, the device can be adapted to a wide assortment of pipes. Research has been carried out regarding the shape and size of a stress concentrator introduced into the sample. Relationships have been derived between the shape of the tensile loading curves and the characteristic forces for different types of stress concentrators. It is proposed to use PSS with stress concentrators to prevent plastic deformation in one of the supporting sections (this also allows to correlate the applied forces to one section). The concentrator should be introduced into the tube wall of the sample as a drilled hole. This method is comparatively simple with respect to established testing methods.

Experimental Estimation of Maximal Ductility and Flow Curves of Titanium Alloys With Hot-Torsion Tests

“…Introduction. Manufacturing of seamless tubes due to the complex strain-stress state in deformation zone requires not trivial approaches to accounting of changes of metal properties [1,2]. In this case prescribing of strain, temperature and speed parameters at hot tube extrusion can be based on results of hot-torsion tests [3 -5].…”