Thermal and mechanical cycling of thin-ply composites for cryogenic applications

Important results from the project

In this project we have investigated the effect of thermo-mechanical cycling of thin ply composites intended for cryogenic hydrogen storage applications. Quasi-static, mechanical fatigue and thermal fatigue tests were performed according to plan. Only a few matrix cracks were observed at very high load and very high number of cycles. Those cracks were initiated but not propagated along the width of the specimens. These results show that the selected thin ply composite, supplied by Oxeon, has the potential to become a viable material solution for future lightweight hydrogen tanks.

Expected long term effects

The test results showed that the material has a high damage onset level and therefore makes it an interesting candidate to make hydrogen composite tanks and pipes. The limited damage indicates that there are no obvious leak paths through the thickness that would compromise the functionality of the material in this application. The material durability under cryogenic operating temperatures looks promising. The project strengthens the research position of Sweden in the area and allows marketing of Oxeon’s material for hydrogen storage applications.

Approach and implementation

Suitable thin ply materials (fibre reinforcement and polymer matrix) were selected, and cross-ply composite laminates were manufactured by filament winding on a flat tool surface. The laminates were inspected for damage, and samples were prepared for testing. The selected materials were supplied by Oxeon. Manufacturing of composite laminates using filament winding, and sample preparation was done by RISE. Quasi-static, thermal fatigue, and mechanical fatigue tests were performed by LiU. Thermal fatigue tests were performed using liquid nitrogen (-196 °C).