Walter L. Bradley

Effect of Seawater on Corrosion Fatigue Behavior of Filament Wound Tubes

P.L. (Ben) Chiou (Research Associate), John Puh (MS student)

The effect of seawater, microbials and cyclic loading on the lifetime of composites is being studied. Long-term durability of filament wound cylinders are critical issues in the use of composite tubulars in offshore drilling and production

Tensile coupons have been soaked in seawater, with and without microbials, for six months and then tested to failure using acoustic emission to monitor damage prior to failure. Results are compared to unsoaked specimens to evaluate effects of seawater and microbials. Filament wound tubes are being tested in cyclic fatigue in the as received condition and after soaking to saturation in seawater. Damage accumulation is monitored using acoustic emission and Spate infrared spectroscopy. The damage scenario will guide modeling and provide critical values for the models.

U. of Houston, Composites Center
NIST

The effect of seawater, microbials, and fatigue stressing which a composite will see in service must be better understood if successful engineering applications of filament wound tubes can move forward.

April 1995 to August 1998

Journal papers describing the following:
1. Corrosion fatigue behavior of filament wound composite tubes
2. Effect of seawater and microbials on tensile behavior of composites

Regular meetings and phone contact with NIST ATP partners
Presented three papers at ASTM meeting on "Environmental Effects on Composites", New Orleans, November 1996; one paper at American Society for Composites, Atlanta, Oct., 1996, several journal publications.