• Dr. Stelios Kyriakides
  • The University of Texas at Austin
  • 3081 Derring Hall
  • 2:00 p.m.
  • Faculty Host: Dr. Kevin Wang

The design of pipelines installed in deep waters is governed by buckling and collapse considerations. An equally important consideration is safeguarding the line against the potential occurrence of a propagating buckle. A buckle that propagates can be initiated from the collapse of a locally damaged section of the pipeline. Once initiated, the buckle propagates at high velocity, and has the potential to quickly destroy the whole line. The lowest pressure at which such a buckle propagates is the propagation pressure, a characteristic pressure of the pipe. The propagation pressure is typically only 15% to 20% of the collapse pressure of an intact pipe, and so designing the line based on the propagation pressure is impractical. The preferred alternative is to base the design on the collapse pressure, and to install buckle arrestors at regular intervals along the pipeline. In the event a propagating buckle is initiated, the arrestors limit the damage to the length of pipe separating the arrestors on either side of the initiation site (typically several hundred meters). Buckle arrestors are devices which locally increase the circumferential bending rigidity of the pipe, and thus provide an obstacle in the path of a propagating buckle. The arrestors are typically thick-walled rings which are slipped over or welded into the pipeline. The lecture will use results from experiments and analysis to review fundamental and practical aspects of the initiation of a propagating buckle, its quasi-static and dynamic propagation, and its arrest, as they influence the design of modern offshore pipelines.

Biography:

Stelios Kyriakides obtained his PhD in aeronautics from the California Institute of Technology in 1980. He joined the Department of Aerospace Engineering and Engineering Mechanics of The University of Texas at Austin in the same year, where he has served as professor since 1989. Currently he is Director of the Center for Research in Mechanics of Solids, Structures and Materials and holder of the Cockrell Family Chair in Engineering No. 10.

Professor Kyriakides’ research focuses on instabilities that limit the extent to which solids, structures and materials can be loaded or deformed. He has published more than 190 technical articles, one book and one monograph. He served as chair of the Executive Committee of the Applied Mechanics Division-ASME, as President of the American Academy of Mechanics (AAM), as chair of the US National Committee of Theoretical and Applied Mechanics, and is Editor of the International Journal of Solids and Structures. His recognitions include the 2009 Warner T. Koiter Medal from the American Society of Mechanical Engineers (ASME), Member of the US National Academy of Engineering, and Fellow of ASME and AAM.

More information about the speaker can be found at http://research.ae.utexas.edu/mssm/faculty/stelios-kyriakides.php.