This is a past event
Prof. J Michael T Thompson, FRS, School of Engineering, University of Aberdeen, and Department of Applied Mathematics and Theoretical Physics, University of Cambridge
Helical buckling and post-buckling of an elastic rod within a cylindrical casing arises in many disciplines, but is particularly important in the petroleum industry. Here, a drill-string, subjected to an end twisting moment combined with axial tension or compression, is particularly prone to buckling within its bore-hole — with potentially serious results. A theoretical study of this instability is presented, giving new results for the advanced stage when the rod is in continuous contact with the cylinder. Results, drawing on a new instability theorem, include rigorous stability analyses and contact pressure assessments. Two approximate solutions give insight, universal graphs and parameters, for the practically relevant case of small angles, and highlight the existence of a critical cylinder diameter. Excellent agreement with experiments is achieved.
- Speaker
- Prof. J Michael T Thompson
- Hosted by
- CADR
- Venue
- FN110