Michael D. Engelhardt

Structural Testing of Composite Tubes

Guillermo Ramirez (PhD student)

Little experimental data are available on the response of thick-walled hybrid composite tubular members under pressure and axial loading. Such data are needed to understand failure criteria, for calibration and verification of computational and design models, and to address the unknowns of scale effects. The objective of this research project is to develop testing capabilities and test data for thick walled hybrid composite tubes, with a focus on the riser theme structure.
This project is part of OTRC's Materials/Structural Integrity Thrust Area. In the OTRC Strategic Research Plan, this project contributes to the "Riser Test Capability" objective in the plan.

In this project, experimental capabilities will be developed for testing large scale composite tubes under axial tension (static and fatigue) and internal pressure. The test facility will include capabilities to evaluate tube response by acoustic emission and by thermal emission. The tube tests will monitor the progression of damage to the composite, from matrix cracking up through ultimate failure of the tube. The type of tests conducted will be determined by the availability of large scale test specimens. In addition, a test will be conducted on a full size carbon fiber drilling riser specimen under external pressure.

Related work on composite production and drilling risers is underway through the NIST program on "Manufacturing Composite Structures for the Offshore Oil Industry." OTRC participation in one of these NIST sponsored projects will be supported by this principal investigator.

The testing capabilities and test data developed as part of this project will assist in developing and validating composite tubular members at a realistic scale. The test facilities will complement others currently available to the oil industry for large scale testing.

October 1993 to September 1997

Facility for testing large scale composite tubular members under axial tension and internal pressure.
Test data on the response and failure characteristics of large scale hybrid composite tubes under various loading conditions.
Evaluation of failure criteria, for various failure modes, including leakage and ultimate failure of composite tubes.