Summary
The objective of this research is to predict the response of hybrid laminates and tubes to hygrothermal and mechanical loads. Both unidirectional hybrid laminates and hybrid laminates containing off-axis piles and analyzed. The influence of the following parameters are studied at the lamina (i.e. in-plane) level:
- interphase properties
- matrix properties
- fiber volume
- carbon to total fiber volume ratios
- debonds
- moisture absorption
- temperature
These parameters are varied to study the effects on the lamina tensile (fiber direction), transverse (perpendicular to the fibers), and in-plane shear response. In addition, the effect of progressive fiber breakage on the axial moduli of hybrid laminae is studied using a statistical model developed by this author. A comparison of unidirectional hybrid laminates with intermingled and non-intermingled fibers is included to illustrate the advantages of intermingling different fiber types in hybrid composites. An analysis procedure is proposed in which the resulting in-plane properties from the lamina level analysis are used to model the laminate level response of the laminates and tubes. The analysis illustrates how the response of TTT hybrid laminates to tension and bending loads and the response of filament would glass and hybrid laminates to tension and bending loads and the response of filament wound glass and hybrid composite tubes to internal pressure may be ascertained beginning with the properties of the individual constituents. The analysis also aids the designer in identifying which of the above parameters should be considered when designing components for use in an offshore environment.
Related Publications: Ross, G.R. and Ochoa, O.O., “Environmental Effects on Unsymmetric Composite Laminates,” Journal of Thermoplastic Composite Materials, Vol. 4, pp 266-284, July 1991.
Ross, G.R. and Ochoa, O.O., “Hygroscopic Response of Hybrid Tubes,” Corrosion95, Paper #140, NACE, Orlando, Florida, March 1995.
Ross, G.R. and Ochoa, O.O.,”Micromechanical Analysis of Hybrid Composites,” Proceedings of the First International Conference on Composite Materials and Energy, Montreal, Canada, May 1995, pp 51-58.
Ochoa, O.O., Ross, G.R. and Liggett, M.G., “Design of Hybrid Composite Tubulars,” Offshore Mechanics and Arctic Engineering Conference, Florence, Italy, June 1996
Ross, G.R. and Ochoa, O.O., “Micromechanical Analysis of Hybrid Composites,” Reinforced Plastics and Composites, 16, pp. 828-836, 1996.
Ochoa, O.O., Ross, G.R., Liggett, G.M., and Farivar-Sadri, K., “Design of Hybrid Composite Tubulars,” Proceedings of the 14th International Conference on Offshore Mechanics and Arctic Engineering, Copenhagen,1996.
