1. International Conference on Hydrogen Safety
RESEARCH ON RC&S FOR HYDROGEN STORAGE RELEVANT TO TRANSPORT AND VEHICLE ISSUES WITH SPECIAL FOCUS ON COMPOSITE CONTAINMENTS
International Conference on Hydrogen Safety
9/12/2011
P. Pöschko, G. Mair, BAM-3.2

2. Structure
Division 3.2 – Pöschko, Mair
Aspects of CC prospective design evaluation: Probabilistic Approval Approach
Assessment of continued CC safety performance: Testing Parallel to Operation
Quantification of CC residual strength properties: Techniques and Strategy

3. Probabilistic Approval Approach
Division 3.2 – Pöschko, Mair
Mathematical analysis of GAUSS log-standard deviation based on 25,000 LC mean value

4. Probabilistic Approval Approach
Division 3.2 – Pöschko, Mair
Safe number of fillings depending on mean values of fatigue figures

5. Testing Parallel to Operation
Division 3.2 – Pöschko, Mair
Degradation of H2G CC composite materials is subject to a variety of in-service conditions  increasing uncertainties in safe life behavior/ residual service life determination
Static loads (creep) are largely responsible for progressive loss of strength  difficulty of predictability, even if underlying mechanisms were well understood
Monitoring seems essential, especially in the face of “unlimited“/several decades‘ service lives

6. Testing Parallel to Operation
Division 3.2 – Pöschko, Mair
Principle for the assessment of safe service lives
99.99%
Schematic diagram for the determination of safe service lives, with degradation lines assumed to run linearly

7. Techniques and Strategy
Division 3.2 – Pöschko, Mair
NDT methods are not yet sophisticated enough to reliably monitor CC populations  necessity of destructive test procedures (key tests)
e. g. 15 y
e. g. 15 y …
Beginning of life/production
End of originally granted service life
Key tests on sample of used CC
Design type approval & original batch tests
Key tests on sample of used CC
Possible life time extension
Comparison and safe life assessment
Possible early rejection

8. Techniques and Strategy
Division 3.2 – Pöschko, Mair
Appropriate testing techniques must account for expected in-service loads and respective damage mechanisms, both for design type approval and parallel to operation:
Cycle tests appear adequate for most designs with metal liners, but
Aspects of creep rupture cannot be simulated in a satisfactory manner at present, making assessment of type IV designs a particular challenge
Discrimination between load cycle sensitive and non-sensitive designs, requires new techniques!

9. Techniques and Strategy
Division 3.2 – Pöschko, Mair
Influence of constant pressure increase rate on burst pressure for one specific design Z1

10. Techniques and Strategy
Division 3.2 – Pöschko, Mair
Strength of artificially aged cylinders in comparison with new cylinders of design Z2

11. Summary and Outlook
Division 3.2 – Pöschko, Mair
Given the complexity of CC designs, current RC&S need improvement with regard to testing procedures and periodic retesting
Unspecific requirements suggest there is potential for cost and weight optimization, depending on the materials and CC design
Destructive testing parallel to operation can provide useful information in order to evaluate service life time determinations
Slow burst techniques will be further developed to allow for better assessment of long-term behavior

12. Please ask your questions now…
RESEARCH ON RC&S FOR HYDROGEN STORAGE RELEVANT TO TRANSPORT AND VEHICLE ISSUES WITH SPECIAL FOCUS ON COMPOSITE CONTAINMENTS
RESEARCH ON RC&S FOR HYDROGEN STORAGE RELEVANT TO TRANSPORT AND VEHICLE ISSUES WITH SPECIAL FOCUS ON COMPOSITE CONTAINMENTS
Please ask your questions now…
International Conference on Hydrogen Safety
9/12/2011
P. Pöschko, G. Mair, BAM-3.2