James Vernon Maple

US Patent:

60002778, Dec 14, 1999

Filed:

Jun 5, 1998

Appl. No.:

9/092530

Inventors:

Marina Quiocho Smith - San Antonio TX
Wei Wang - Columbia MD
Carl Harry Popelar - San Antonio TX
James Alan Maple - Baytown TX

Assignee:

Southwest Research Institute - San Antonio TX

International Classification:

G01M 302
G01B 530

US Classification:

73 37

Abstract:

A method of predicting rupture failure for corroded transmission pipelines uses a model that accounts for the effects of residual and thermal stresses, and settlement of the pipe following installation. The pressure required for failure under a fixed bending moment is different from the pressure required wherein the same bending moment is produced by the settlement of the pipe because the bending compliance increases with plastic straining. The failure criterion depends upon whether or not the hoop strain exceeds the difference between the ultimate hoop strain limit of the material and the remaining hoop strain capacity needed for the material to shed the axial stresses due to bending.