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Technology
Assessment & Research (TA&R) Program
| Project
Number |
72 |
| Date of Summary |
March 31, 1986 |
| Subject |
Torsional Evaluation of
Stiffening Members in Marine Structures |
| Performing Activity |
Lehigh University |
| Principal Investigator |
Dr. Alexis Ostapenko |
| Contracting Agency |
Maritime Administration |
| Estimated Completion |
Completed |
| Description |
The objective was to obtain an
accurate description of the ultimate and post-disaster strength of offshore platforms and
other marine structures. This research will consist of:
(1) a critical review of current rules and methods for
considering the tripping (buckling) behavior of symmetrical and asymmetrical stiffening
elements;
(2) development of new solutions to fill any deficiencies
of current analysis methods, especially at and beyond ultimate capacity;
(3) the testing of model specimens for the purpose of
checking critical assumptions.
The project is expected to improve the reliability and
accuracy of the design rules for the tripping mode and to prove a means for including this
mode in the investigation of the ultimate and post- disaster of marine structures. |
| Progress |
Completed. Comparison of the
method developed for considering the effect of initial imperfections and the test results
which assumed some levels of imperfection, pointed out a need for further work. The method
was revised to include two additional coordinate functions in the deformation field so the
interaction between the buckling modes of the stiffener and plate could be considered
directly. The additional coordinate functions are constant curvature and sine squared. The
results indicate that the effect of the stiffener web deformation appears to be relatively
small. The method will be checked for accuracy of the new formulation and programmed for
use in a parametric study. |
| Reports |
AB
(62 pages) |
Chu, P. C., Ostapenko, A.,
Torsional Strength of Longitudinales in Marine Structures, Final Report, F.E.L. Report No.
492.3, Lehigh University, Bethlehem, Pennsylvania, January 1986. |
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