John L. Tassoulas

Finite Element Analysis of Composite Risers

Hayder A. Rasheed, Prashant W. Andrade, and Luis F.G. Vasquez (PhD students)

Investigation of behavior and strength of composite tubes under tension, bending and pressure
Assessment of the effects of delamination buckling and growth on the collapse pressure of composite tubes
Development of computational capability for dynamic analysis of composite risers recognizing the interaction between material layers in the wall of the tube

Provides composite structural analysis models
Contributes data relevant in composite riser design

Use specially formulated tubular shell finite elements
Select and adopt appropriate constitutive equations and failure criteria for the materials at hand (data provided by W.L. Bradley, H.L. Marcus and R.A. Schapery)
Apply fracture mechanics to delamination growth
Perform nonlinear analysis
Compare with experimental results (data provided by M.D. Engelhardt)

Performance of composite tubes (P. Odru, IFP)
Failure criteria (S.R. Swanson, University of Ohio)
Collapse tests (S.S. Wang, University of Houston)

This research will provide computational tools for:

1. nonlinear dynamic analysis of composite risers
2. estimation of composite tube strength

October 1992 to September 1997

Finite element model for the study of tube behavior and strength under combined loads
Procedure for nonlinear dynamic analysis of composite risers

Rasheed, H.A. and Tassoulas, J.L.,"Behavior and Strength of Composite Tubes Considering Delaminations and Other Defects," Offshore Technology Research Center Report 8/96-B8375, August 1996.
Rasheed, H.A., and Tassoulas, J.L., "Strength Evaluation of Composite Risers," Paper No. 7826, Offshore Technology Conference, Houston, Texas, May 1-4, 1995.
Rasheed, H.A., and Tassoulas, J.L., "Effects of Delamination on Composite Tubes Subjected to External Pressure," Sixth International Offshore and Polar Engineering Conference, Los Angeles, California, May 26-31, 1996.
Referred Journal Articles NIST Project