The strength-grade of pipeline steels used for transportation of gases has been increasing to reduce the cost of the overall pipeline system. Along with higher strength, adequate fracture toughness and resistance to plastic buckling are required of pipes installed in earthquake- or frost-prone regions. To get higher strength with adequate deformability in low-alloy pipeline steels, plates for pipes are typically made today by thermomechanically-controlled rolling processes, which introduce strong crystallographic texture and anisotropy in the pipes. The plates are then cold-formed into pipes, which introduces further anisotropy and residual stresses in the pipe. In the current work, effects of various steps of the pipe manufacturing process, such as rolling, cold forming, etc., on residual stress, hardening moduli, plastic anisotropy, and eventually, to the buckling resistance of the pipe, are studied. Effects of various types of geometric perturbation on plastic buckling response of pipes are also studied. Due to the crystallographic texture and cold-forming, crystal plasticity-based constitutive models instead of Mises plasticity-based constitutive models may be better suited to model the pipe. In the current work, crystal plasticity-based material models are used to predict the buckling response of pipes. Results show that the buckling strain in uniaxial compression, predicted using a crystal plasticity-based model, is 20 % less than the one predicted using an 'equivalent' Mises plasticity-based model, for a pipe with d/t ratio of 51. Further results show that variation in material properties and residual stresses caused by cold forming reduces the buckling strain by about 30 %, for a pipe with d/t ratio of 51.
Plastic buckling in gas transmission line-pipes, cold formed from thermo-mechanically-controlled rolling of low-alloy steel plates
Plastisches Ausbeulen in Gaspipelines aus durch Kaltumformung nach thermomechanischem Walzen hergestellten niedriglegierten Stahlblechen
2007
164 Seiten, 64 Bilder, 1 Tabelle, 66 Quellen
Hochschulschrift
Englisch
Axisymmetric Buckling of Elastic-Plastic Annular Plates
AIAA | 1974
|Plastic Buckling of Simply Supported Compressed Plates
NTRS | 1949
|Plastic buckling of plates and shells under biaxial loading
TIBKAT | 1968
|Plastic Buckling of Rectangular Plates Subjected to Combined Loads
British Library Conference Proceedings | 1998
|Experimental results from buckling behavior of steel shear plates
Tema Archiv | 1992
|