RESEARCH ON RC

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RESEARCH ON RCS 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

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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

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Probabilistic Approval Approach
Division 3.2 Pöschko, Mair
Mathematical analysis of GAUSS log-standard
deviation based on 25,000 LC mean value
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Probabilistic Approval Approach
Division 3.2 Pöschko, Mair
Safe number of fillings depending on mean values
of fatigue figures
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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

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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
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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
Key tests on sample of used CC
Design type approval original batch tests
Possible life time extension
Comparison and safe life assessment
Possible early rejection
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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!

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Techniques and Strategy
Division 3.2 Pöschko, Mair
Influence of constant pressure increase rate on
burst pressure for one specific design Z1
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Techniques and Strategy
Division 3.2 Pöschko, Mair
Strength of artificially aged cylinders in
comparison with new cylinders of design Z2
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Summary and Outlook
Division 3.2 Pöschko, Mair

• Given the complexity of CC designs, current RCS
  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

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RESEARCH ON RCS FOR HYDROGEN STORAGE RELEVANT TO
TRANSPORT AND VEHICLE ISSUES WITH SPECIAL FOCUS
ON COMPOSITE CONTAINMENTS
RESEARCH ON RCS 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