Overall the project was a success to show the hybrid design is a viable solution to reduce fiber usage, thus driving down the cost of fuel storage vessels. Alternative fiber was also investigated in this project, but the added mass impacted the vessel cost negatively due to the lower performance from the alternative fiber. The original in-house software was developed for filament winding only. To design a vessel that passed these tests, the in-house modeling software was updated to add more » capability to start and stop fiber layers to simulate the AFP process. It was discovered the location where AFP and FW overlap for load transfer could be weakened during hydraulic cycling at 85☌. The tests passed include burst test, cycle test, accelerated stress rupture test and drop test. The latest vessel design passed all the critical tests on the hybrid design per European Commission (EC) 79-2009 standard except the extreme temperature cycle test.

A numbers of vessels were manufactured in this project. The objective of this project is to develop new methods for manufacturing Type IV pressure vessels for hydrogen storage with the purpose of lowering the overall product cost through an innovative hybrid process of optimizing composite usage by combining traditional filament winding (FW) and advanced fiber placement (AFP) techniques. Carbon fiber is the greatest cost driver in building a hydrogen pressure vessel. Existing filament winding processes produce a pressure vessel that is structurally inefficient, requiring more carbon fiber for manufacturing reasons, than would otherwise be necessary. Department of Energy (DOE) defined a need for low-cost gaseous hydrogen storage vessels at 700 bar to support cost goals aimed at 500,000 units per year.

3.2.3 testout lab