# On board 70 MPpa hydrogen composite pressure vessel safety factor

Stéphane Villalonga, T. Laguionie, J. Toulc'hoat, B Desprez, G. Baudry, M.

Ramage, T. Delhoume, C. Hameon

► To cite this version:

Stéphane Villalonga, T. Laguionie, J. Toulc'hoat, B Desprez, G. Baudry, et al.. On board 70 MPpa hydrogen composite pressure vessel safety factor. ICHS 2021 - International conference on hydrogen safety 2021, Hysafe, Sep 2021, Édimbourg, United Kingdom. hal-05470064

HAL Id: hal-05470064

https://hal.science/hal-05470064v1

Submitted on 21 Jan 2026

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
<figure><img src="image_2.png" /></figure>

DE LA RECHERCHE À L'INDUSTRIE

# 70 MPa H₂ on-board CPV safety factor

22 September 2021

Stéphane Villalonga
What is behind the safety factor
looking at 70 MPa Type IV Composite
Pressure Vessel at material level?

<figure><img src="image_3.png" /></figure>
1. CEA

2. Type IV Composite Pressure vessel

3. Material performance variability

4. 70 MPa Type IV safety factor

5. Conclusion & Perspective
<figure><img src="image_4.png" /></figure>

<figure><img src="image_5.png" /></figure>

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /></figure>

<figure><img src="image_10.png" /></figure>

The CEA is active in four main areas:

* low-carbon energies

* defense and security

* information technologies

* health technologies

https://www.cea.fr/

10 research centres

19 925 technicians, engineers, researchers and staff

1 351 PhD & Post Doc

750 priority patents filed / year

200 start-ups since 1972 in the innovative technologies sector

<figure><img src="image_11.png" /></figure>

CEA is “The World's most innovative research institution”

(Reuters, 8th of March, 2016)

<figure><img src="image_12.png" /></figure>
# 1) CEA H₂ 70 MPa CPV R&D activity since 2002 at CEA Tours (Le Ripault)

## CPV: Composite Pressure Vessel

<figure><img src="image_13.png" /><figcaption>Dedicated R&D CPV plateform at CEA</figcaption></figure>

* **Materials**

* Polymer synthesis and transformation

* Characterisation and H₂ permeation

* New Fastcuring Towpreg

FASTCURE 2

ANR

S2&2

* **CPV Concept & Design & Mech. Simulation (FE calculation)**

* **Fiwiqus**: CEA filament winding tool for Abaqus

* **Process and simulation** (reactive/non reactive Rotomolding, Filament Winding, Curing...)

* **Manufacturing** (Liner, Composite)

* **Instrumentation**

* **Testing Process**: Proof, Burst, Cycling Test, Creep, Flaw, Gun, Impact, Fire, Chem, Proof ...

* **CPV Testing** (Standard, Regulation EC79 or R134, additional severe conditions)

* **PHM, SHM**

* **RCS participation** (AFNOR, ISO-TC197, EC-SFEM, UNECE-GTR13)

* **HRS: Fast Filling** (FCH-JU PRHYDE Project)

<figure><img src="image_14.png" /></figure>

<figure><img src="image_15.png" /></figure>

* **CPV prototyping and testing**

* **R&D collaborative projects** (with academics, industrials)

* **Industrial transfer** (ex. Liner manufacturing to RAIGI)

* **Patents, IP** (7 + 4)

* **Education**

* **Conference** (H2PV http://h2pv.org/, ICHS, ICCM 27 - 31 July 2009 Edinburgh, others)

* **Expertise**

* **Consulting** (industrials, end-users)

<figure><img src="image_16.png" /></figure>
<figure><img src="image_17.png" /></figure>

<figure><img src="image_18.png" /></figure>

<figure><img src="image_19.png" /></figure>

<figure><img src="image_20.png" /></figure>

<figure><img src="image_21.png" /></figure>

<figure><img src="image_22.png" /><figcaption>Full thermoplastic CEA H₂ 37L 700 bar CPV</figcaption></figure>

<figure><img src="image_23.png" /><figcaption>CEA H₂ 62L 700 bar CPV</figcaption></figure>
# 1) Testing and Certification tests at CEA (EC79 & R134)

<figure><img src="image_24.png" /></figure>

<figure><img src="image_25.png" /></figure>

<figure><img src="image_26.png" /></figure>

<figure><img src="image_27.png" /></figure>

<figure><img src="image_28.png" /></figure>

<figure><img src="image_29.png" /></figure>

<figure><img src="image_30.png" /></figure>

<figure><img src="image_31.png" /></figure>

<figure><img src="image_32.png" /></figure>

<figure><img src="image_33.png" /></figure>

<figure><img src="image_34.png" /></figure>

<figure><img src="image_35.png" /></figure>

<figure><img src="image_36.png" /></figure>
<figure><img src="image_37.png" /></figure>

<figure><img src="image_38.png" /></figure>

1 tow of 24k filaments
7µm filament diameter

<figure><img src="image_39.png" /></figure>

CEA Filament Winding process
<figure><img src="image_40.png" /></figure>

* For the composite

* Toray T700 carbon fibre

* Epoxy resin

* For the liner

* Poly-ethylene

* Poly-amide

* For the boss

* Aluminum 6061

<figure><img src="image_41.png" /></figure>

<figure><img src="image_42.png" /></figure>

<figure><img src="image_43.png" /></figure>

<figure><img src="image_44.png" /></figure>

<figure><img src="image_45.png" /></figure>

<figure><img src="image_46.png" /></figure>

<figure><img src="image_47.png" /></figure>

### Variability

* Fiber strength

* Composite strength

* Fibre Volume Fraction

* Porosity

* Inter Laminar Shear strength
<figure><img src="image_48.png" /></figure>

### Sensitivity

* Resin & temperature

* Resin & water

* Stress relaxation

* Tg

<figure><img src="image_49.png" /></figure>
<table><thead><tr><th></th><th>17,5</th><th>35</th><th>52,5</th><th>70</th><th>87,5</th><th>105</th><th>122,5</th><th>140</th><th>157,5</th><th>175</th><th>192,5</th></tr><tr><th></th><th colspan="2">Nominal</th><th colspan="2">Maximum</th><th colspan="2">Minimum</th><th colspan="2">Mean Burst Pressure (MeanBP)</th><th colspan="2">MeanBP -10%</th><th colspan="2">MeanBP +10%</th></tr><tr><th></th><th colspan="2">Working Pressure</th><th colspan="2">Filling Pressure</th><th colspan="2">Burst Pressure</th><th colspan="2"></th><th colspan="2"></th><th colspan="2"></th></tr></thead><tbody><tr><td>Pressure (MPa)</td><td colspan="14"></td></tr><tr><td>70 MPa On-board H2 CPV Pressure (MPa)</td><td>2</td><td>70</td><td>87.5</td><td>105</td><td colspan="12"></td></tr><tr><td>Working Pressure Range</td><td colspan="14"></td></tr><tr><td>Absolute Pressure Safety Margin value (MPa)</td><td colspan="14">70 MPa</td></tr><tr><td>Burst ratio value</td><td>1</td><td>1,25</td><td>1,5</td><td>1,75</td><td>2</td><td>2,25</td><td>2,5</td><td colspan="2"></td><td>2,75</td><td colspan="2"></td></tr><tr><td>Safety Factor Value</td><td colspan="14"></td></tr><tr><td></td><td>1</td><td>1,2</td><td>1,4</td><td>1,6</td><td>1,8</td><td>2</td><td colspan="2"></td><td>2,2</td><td colspan="2"></td></tr></tbody></table>
http://www.hycomp.eu/

<figure><img src="image_50.png" /></figure>

FCH-JU Hycomp Project
1.6 SF for UD (20 years)=> 52MPa

Composite Structure +
Temperature, Humidity, Porosity,
Fibre volume fraction effetcs margin
(17,5 MPa)
25%

<figure><img src="image_51.png" /></figure>

<table><tr><td>Pressure safety Margin (70 MPa)</td><td>70 MPa</td><td>100%</td></tr><tr><td>UD Carbon Epoxy margin (52 MPa)</td><td>52 MPa</td><td>75%</td></tr><tr><td>Temperature, Humidity, Porosity, Fibre volume fraction effetcs margin (17,5 MPa) + Composite Structure</td><td>17.5 MPa</td><td>25%</td></tr></table>

Both experimental and analytical results were used to estimate a safety factor which covers intrinsic materials properties. It was called intrinsic safety factor (iSF)
* 70 MPa H₂ CPV in public area during 15 or 20 years lifetime (car, truck, train, bus...).

* On-board 70 MPa H₂ carbon CPV technology: 2.25 burst pressure ratio, equivalent 1.8 safety factor and an absolute pressure margin of 70 MPa.

* Considering Hycomp project experimental-based results : Intrinsic-safety factor of the carbon uni-directional composite material itself corresponds to **an absolute pressure margin of 52 MPa for 20 years service life**.

* An absolute pressure margin of 17.5 MPa is remaining to take into account during the lifetime of the vessel

• the effect of structure compared to Uni-Directional composite

• the effect of temperature

• the effect of humidity

• and composite quality (porosity, fibre volume ratio)

increase in damage
accumulation rate
=> reducing lifetime
It seems necessary to

* increase the knowledge on the behaviour of the material under conditions close to the use to **confirm** the previous absolute pressure margins (52 MPa for UD, 17,5 MPa for structure + temperature + humidity + quality)

* carry out tests of thermo-mechanical or hydro-thermo-mechanical fatigue by combining

* water

* thermal

* and mechanical oscillations

* making it possible to apprehend, statistically, damage kinetics on materials such as tanks (with or without defects).
Thanks for your attention

cea