Skip to content

docs(pages): 水素タンク設計ノート公開ページ + ロードマップからのリンク #38

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
keisuke58 merged 1 commit into from
Aug 2, 2026
+307 −0
Merged

docs(pages): 水素タンク設計ノート公開ページ + ロードマップからのリンク #38

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
306 changes: 306 additions & 0 deletions docs/hydrogen-tank.html
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,306 @@
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Hydrogen Tank SHM — Design Note</title>
<meta name="description" content="Design note: extending the H3 fairing GNN-SHM stack to the cryogenic LH2 hydrogen tank — geometry, materials, loading, defects, graph features, and the one-sample FEM plan.">
<style>
:root{
--bg:#f4f6f9; --surface:#ffffff; --surface-2:#eef2f7;
--ink:#0f1720; --muted:#5b6875; --line:#d7dee7;
--accent:#1f6feb; --cryo:#0995b4; --amber:#b7791f;
--good:#158a66;
--grid:rgba(9,149,180,.06);
--shadow:0 1px 2px rgba(15,23,32,.06),0 8px 24px rgba(15,23,32,.05);
}
@media (prefers-color-scheme:dark){
:root{
--bg:#0a0f16; --surface:#111a24; --surface-2:#0d141d;
--ink:#e7eef6; --muted:#8b9aa9; --line:#1e2a38;
--accent:#4d9bff; --cryo:#38c6e0; --amber:#e0a83a;
--good:#2fbf94;
--grid:rgba(56,198,224,.08);
--shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px rgba(0,0,0,.35);
}
}
:root[data-theme="light"]{
--bg:#f4f6f9; --surface:#ffffff; --surface-2:#eef2f7;
--ink:#0f1720; --muted:#5b6875; --line:#d7dee7;
--accent:#1f6feb; --cryo:#0995b4; --amber:#b7791f;
--good:#158a66;
--grid:rgba(9,149,180,.06);
--shadow:0 1px 2px rgba(15,23,32,.06),0 8px 24px rgba(15,23,32,.05);
}
:root[data-theme="dark"]{
--bg:#0a0f16; --surface:#111a24; --surface-2:#0d141d;
--ink:#e7eef6; --muted:#8b9aa9; --line:#1e2a38;
--accent:#4d9bff; --cryo:#38c6e0; --amber:#e0a83a;
--good:#2fbf94;
--grid:rgba(56,198,224,.08);
--shadow:0 1px 2px rgba(0,0,0,.4),0 10px 30px rgba(0,0,0,.35);
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
margin:0; background:var(--bg); color:var(--ink);
font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
line-height:1.6; -webkit-font-smoothing:antialiased;
background-image:linear-gradient(var(--grid) 1px,transparent 1px),
linear-gradient(90deg,var(--grid) 1px,transparent 1px);
background-size:44px 44px;
}
.wrap{max-width:1000px;margin:0 auto;padding:clamp(28px,5vw,64px) clamp(20px,4vw,40px)}
.eyebrow{font-family:ui-monospace,"SF Mono",Menlo,Consolas,monospace;
font-size:12px;letter-spacing:.18em;text-transform:uppercase;color:var(--cryo);font-weight:600}

.toggle{position:fixed;top:14px;right:14px;z-index:10;
font-family:ui-monospace,monospace;font-size:11px;letter-spacing:.08em;text-transform:uppercase;
background:var(--surface);color:var(--muted);border:1px solid var(--line);border-radius:20px;
padding:7px 13px;cursor:pointer;box-shadow:var(--shadow)}
.toggle:hover{color:var(--ink)}
.toggle:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

.back{display:inline-flex;align-items:center;gap:7px;font-family:ui-monospace,monospace;
font-size:12.5px;color:var(--accent);text-decoration:none;margin-bottom:20px}
.back:hover{text-decoration:underline}

header{border-bottom:1px solid var(--line);padding-bottom:30px;margin-bottom:16px}
h1{font-size:clamp(28px,4.5vw,44px);line-height:1.06;margin:12px 0 12px;
font-weight:800;letter-spacing:-.02em;text-wrap:balance;max-width:18ch}
h1 .hl{color:var(--cryo)}
.lede{font-size:clamp(15px,1.8vw,18px);color:var(--muted);max-width:62ch;margin:0}
.status{margin-top:18px;font-family:ui-monospace,monospace;font-size:12px;color:var(--muted)}
.status b{color:var(--amber)}

section{margin:44px 0}
h2{font-size:clamp(19px,2.4vw,24px);font-weight:750;letter-spacing:-.01em;margin:6px 0 16px}
p.body{max-width:64ch;color:var(--ink)}
.muted{color:var(--muted)}

.tablewrap{overflow-x:auto;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);background:var(--surface);margin-top:6px}
table{border-collapse:collapse;width:100%;min-width:560px;font-size:13.5px}
caption{text-align:left;font-family:ui-monospace,monospace;font-size:11px;letter-spacing:.1em;text-transform:uppercase;
color:var(--muted);padding:13px 16px 0}
th,td{text-align:left;padding:12px 16px;vertical-align:top;border-bottom:1px solid var(--line)}
thead th{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:600;font-family:ui-monospace,monospace}
thead th.tank{color:var(--cryo)}
tbody tr:last-child td{border-bottom:none}
td.rowlab{font-weight:640;color:var(--muted);white-space:nowrap}
td.tank{color:var(--ink);background:color-mix(in srgb,var(--cryo) 6%,transparent)}
td.num{font-variant-numeric:tabular-nums}

.assets{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:6px}
.abox{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:18px;box-shadow:var(--shadow)}
.abox h3{margin:0 0 10px;font-size:13px;font-family:ui-monospace,monospace;letter-spacing:.08em;text-transform:uppercase}
.abox.reuse h3{color:var(--good)} .abox.build h3{color:var(--cryo)}
.abox ul{margin:0;padding-left:18px;display:flex;flex-direction:column;gap:7px}
.abox li{font-size:13.5px}
.abox code,td code,p.body code{font-family:ui-monospace,monospace;font-size:12px;color:var(--accent)}

.steps{counter-reset:s;display:flex;flex-direction:column;gap:2px;margin-top:4px}
.step{display:grid;grid-template-columns:auto 1fr;gap:16px;padding:16px 0;border-bottom:1px solid var(--line)}
.step:last-child{border-bottom:none}
.step .n{counter-increment:s;font-family:ui-monospace,monospace;font-size:13px;font-weight:700;color:var(--cryo);
border:1px solid color-mix(in srgb,var(--cryo) 45%,transparent);border-radius:8px;width:34px;height:34px;
display:flex;align-items:center;justify-content:center}
.step .n::before{content:counter(s,decimal-leading-zero)}
.step h3{margin:2px 0 3px;font-size:15px;font-weight:660}
.step p{margin:0;font-size:13.5px;color:var(--muted)}

.miles{display:flex;flex-direction:column;gap:0;margin-top:4px;border-left:2px solid var(--line);padding-left:20px}
.mile{position:relative;padding:12px 0}
.mile::before{content:"";position:absolute;left:-27px;top:16px;width:10px;height:10px;border-radius:50%;
background:var(--surface);border:2px solid var(--cryo)}
.mile .k{font-family:ui-monospace,monospace;font-size:12px;font-weight:700;color:var(--cryo)}
.mile p{margin:3px 0 0;font-size:13.5px;color:var(--ink)}

.note{background:color-mix(in srgb,var(--amber) 8%,var(--surface));border:1px solid color-mix(in srgb,var(--amber) 40%,var(--line));
border-radius:10px;padding:14px 16px;font-size:13px;color:var(--ink);margin-top:8px}
.note b{color:var(--amber)}

ul.open{margin:6px 0 0;padding-left:18px;display:flex;flex-direction:column;gap:7px;max-width:64ch}
ul.open li{font-size:14px}

footer{margin-top:52px;padding-top:20px;border-top:1px solid var(--line);
font-family:ui-monospace,monospace;font-size:11.5px;color:var(--muted);
display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}
footer a{color:var(--accent);text-decoration:none}
footer a:hover{text-decoration:underline}

@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
@media (max-width:720px){ .assets{grid-template-columns:1fr} }
</style>
</head>
<body>
<button class="toggle" id="themeToggle" type="button" aria-label="Toggle color theme">◑ Theme</button>
<div class="wrap">
<a class="back" href="index.html">← Roadmap</a>
<header>
<div class="eyebrow">GNN-SHM · Design Note</div>
<h1>Hydrogen Tank SHM <span class="hl">(LH2)</span></h1>
<p class="lede">Extending the established H3 fairing GNN-SHM stack to the cryogenic hydrogen tank. The damage physics differ from the fairing, but the pipeline transfers with a small, targeted set of additions.</p>
<div class="status">Status: <b>Design phase</b> — not yet implemented. Numbers below are design assumptions (require FEM / literature verification).</div>
</header>

<section>
<div class="eyebrow">01 — Geometry</div>
<h2>Geometry</h2>
<div class="tablewrap">
<table>
<caption>Table 1 — Modeling assumptions</caption>
<thead><tr><th>Item</th><th>Design assumption</th><th>Note</th></tr></thead>
<tbody>
<tr><td class="rowlab">Target</td><td>H3 upper-stage LH2 tank — cylindrical shell + domes</td><td class="muted">Exact dimensions non-public → representative values</td></tr>
<tr><td class="rowlab">Diameter</td><td class="num">φ ≈ 5.2 m</td><td class="muted">Representative upper-structure diameter</td></tr>
<tr><td class="rowlab">Model</td><td>Symmetric sector (1/6–1/12) + circumferential symmetry BC</td><td class="muted">Same approach as the fairing generator</td></tr>
<tr><td class="rowlab">Regions</td><td>Barrel + dome + <b>weld land</b></td><td class="muted">Weld lines modeled explicitly (defect-prone)</td></tr>
</tbody>
</table>
</div>
<p class="body muted" style="margin-top:14px">Reuses the sector generation, symmetry BCs, and mesh control logic from <code>generate_fairing_dataset.py</code> / <code>generate_realistic_fairing.py</code>.</p>
</section>

<section>
<div class="eyebrow">02 — Materials</div>
<h2>Cryogenic material shift</h2>
<p class="body">Primary target: <b>Al-Li alloy</b> (H-IIA/H3 tank heritage, e.g. 2219 / 2195). The essence is the property shift from room temperature (RT) to liquid-hydrogen temperature (LH2, −253 °C / 20 K).</p>
<div class="tablewrap">
<table>
<caption>Table 2 — RT → cryogenic property shift (design assumption)</caption>
<thead><tr><th>Property</th><th>RT (design)</th><th class="tank">Cryo (LH2, design)</th><th>Trend</th></tr></thead>
<tbody>
<tr><td class="rowlab">Young's modulus E</td><td class="num">~70–78 GPa</td><td class="tank num">+5–15 %</td><td>Increase</td></tr>
<tr><td class="rowlab">Yield strength σy</td><td class="num">~380–450 MPa</td><td class="tank num">+15–30 %</td><td>Increase</td></tr>
<tr><td class="rowlab">Elongation</td><td class="num">~10–12 %</td><td class="tank">Decrease</td><td><b>Embrittlement</b></td></tr>
<tr><td class="rowlab">CTE α</td><td class="num">~23×10⁻⁶/℃</td><td class="tank">Integrated CTE drops (use contraction)</td><td>Decrease</td></tr>
</tbody>
</table>
</div>
<div class="note"><b>⚠ Design assumption.</b> Ranges are from literature and must be fixed against material data (JAXA / references) before implementation. Future line — CFRP composite cryotank — swaps the material model (microcracking + hydrogen permeability).</div>
</section>

<section>
<div class="eyebrow">03 — Loading</div>
<h2>Loading</h2>
<p class="body">Unlike the fairing (thermal CTE + static), the tank superimposes:</p>
<ul class="open">
<li><b>Internal pressure</b> — operational fill/flight pressure</li>
<li><b>Cryogenic thermal stress</b> — constrained contraction from RT → 20 K</li>
<li><b>Fill-cycle fatigue</b> — repeated pressurization / thermal cycling</li>
<li><b>Elastic-wave excitation</b> (GW dynamic analysis) — 50–300 kHz actuation</li>
</ul>
<p class="body muted" style="margin-top:12px">Static analysis (defect stress concentration) and GW dynamic analysis (sensor time-histories) run in parallel — the same two-branch structure as the fairing.</p>
</section>

<section>
<div class="eyebrow">04 — Defect models</div>
<h2>Defect models</h2>
<div class="tablewrap">
<table>
<caption>Table 3 — Defect physics &amp; modeling</caption>
<thead><tr><th>Defect</th><th>Physics</th><th>Modeling</th><th>Fairing analog</th></tr></thead>
<tbody>
<tr><td class="rowlab">Weld flaw</td><td>Porosity / lack-of-fusion / cracks on weld line</td><td>Stiffness/continuity loss on weld line (element weakening or cohesive)</td><td class="muted">— (new)</td></tr>
<tr><td class="rowlab">Thermal-cycle microcrack</td><td>Micro-cracking from cryogenic cycling</td><td>Local stiffness loss + partial contact discontinuity</td><td class="muted">Similar to delamination</td></tr>
<tr><td class="rowlab">Insulation debond</td><td>Foam / MLI insulation separation</td><td>Interface cohesive degradation</td><td class="muted"><b>Same type as skin-core debond</b></td></tr>
<tr><td class="rowlab">H-embrittlement</td><td>Toughness loss from hydrogen embrittlement</td><td>Material toughness reduction (sensitivity study)</td><td class="muted">Handled on the UQ side</td></tr>
</tbody>
</table>
</div>
<p class="body muted" style="margin-top:14px">The cohesive/CZM implementations in <code>generate_cohesive_fairing.py</code> / <code>generate_czm_sector12.py</code> apply directly to insulation debond and weld-flaw interfaces.</p>
</section>

<section>
<div class="eyebrow">05 — Graph &amp; features</div>
<h2>Graph &amp; features — deltas only</h2>
<p class="body">The existing static graph uses <b>34-dim node features</b> (<code>build_graph.py</code>). For the tank, keep the base schema and <b>add only a few dimensions</b>:</p>
<ul class="open">
<li><code>internal_pressure_flag</code> / local pressure stress components (+1–3 dim)</li>
<li><code>cryo_property_delta</code> — shift from RT properties (E/α scalarized, +1–2 dim)</li>
<li><code>weld_line_flag</code> — boundary flag for weld-adjacent nodes (+1 dim, extends existing boundary flags)</li>
</ul>
<div class="note" style="background:color-mix(in srgb,var(--cryo) 8%,var(--surface));border-color:color-mix(in srgb,var(--cryo) 40%,var(--line))">
<b style="color:var(--cryo)">Design principle.</b> Do not create a new schema — add minimal deltas to the existing 34 dims, so <code>train.py</code> / <code>models.py</code> / DA / conformal connect with no modification. Fiber-orientation dims are zero-filled for isotropic Al-Li (revived for the CFRP cryotank).
</div>
</section>

<section>
<div class="eyebrow">06 — Reuse map</div>
<h2>Reuse map</h2>
<div class="tablewrap">
<table>
<caption>Table 4 — What connects, and how much changes</caption>
<thead><tr><th>Existing asset</th><th>Role for the tank</th><th>Change</th></tr></thead>
<tbody>
<tr><td class="rowlab"><code>build_graph.py</code> / <code>build_gw_graph.py</code></td><td>Graph construction</td><td>+few feature dims only</td></tr>
<tr><td class="rowlab"><code>train.py</code> / <code>train_gw.py</code></td><td>Training</td><td><b>No change</b> (swap <code>--data_dir</code>)</td></tr>
<tr><td class="rowlab"><code>models.py</code> (GAT/GCN/GIN/SAGE …)</td><td>Models</td><td>No change</td></tr>
<tr><td class="rowlab"><code>domain_adapt.py</code> / <code>payload_da_gw.py</code></td><td>Ambient-test → cryo-operation sim2real</td><td>No change (pass X matrix)</td></tr>
<tr><td class="rowlab">OGW conformal</td><td>Leak-risk decision with FPR guarantee</td><td>Re-set threshold / cost</td></tr>
<tr><td class="rowlab"><code>fairing_stage2.py</code></td><td>Stage-2 characterization (crack size / leak rate)</td><td>Tank-specific labels</td></tr>
<tr><td class="rowlab">Temperature-robustness framework</td><td>Cryo = extreme operating point</td><td>Extend operating point to 20 K</td></tr>
<tr><td class="rowlab"><code>pce_driver.py</code> / reliability</td><td>UQ for embrittlement / toughness</td><td>Tank-specific uncertainty variables</td></tr>
</tbody>
</table>
</div>
<p class="body" style="margin-top:14px"><b>The only substantially new code is the FEM generator</b> (see below).</p>
</section>

<section>
<div class="eyebrow">07 — One-sample plan</div>
<h2>How the tank line starts</h2>
<p class="body muted">Per project practice — <b>validate one sample first</b>, then batch.</p>
<div class="steps">
<div class="step"><div class="n"></div><div>
<h3>FEM generation</h3>
<p>New <code>src/generate_cryotank_dataset.py</code> (based on the fairing generator): Al-Li cylinder with internal pressure + cryogenic thermal stress, weld-line and thermal-cycle crack defects. Healthy, 1 sample.</p></div></div>
<div class="step"><div class="n"></div><div>
<h3>ODB extraction</h3>
<p>Reuse <code>extract_odb_results.py</code> as-is.</p></div></div>
<div class="step"><div class="n"></div><div>
<h3>Graph &amp; visual check</h3>
<p>Reuse <code>build_graph.py</code>; eyeball one graph (feature distributions, defect labels) before scaling.</p></div></div>
<div class="step"><div class="n"></div><div>
<h3>Batch → same flow</h3>
<p>If OK, expand the DOE → <code>run_batch.py</code>, then the identical fairing flow (train → DA → conformal → Stage-2).</p></div></div>
</div>

<h2 style="margin-top:36px">Milestones</h2>
<div class="miles">
<div class="mile"><span class="k">M1</span><p>Healthy 1-sample generation → graph visual OK (this note's validation).</p></div>
<div class="mile"><span class="k">M2</span><p>One sample per defect type → verify physical plausibility of stress concentration / waveform change.</p></div>
<div class="mile"><span class="k">M3</span><p>DOE batch (N ≈ 100) → detection baseline with <code>train.py</code>.</p></div>
<div class="mile"><span class="k">M4</span><p>Ambient ↔ cryo domain adaptation + conformal → leak-risk FPR guarantee.</p></div>
<div class="mile"><span class="k">M5</span><p>Stage-2 characterization (crack size / leak rate) → go/no-go prognosis.</p></div>
</div>
</section>

<section>
<div class="eyebrow">08 — Open items</div>
<h2>Risks &amp; open items</h2>
<ul class="open">
<li>Confirmed cryogenic properties / toughness of Al-Li (Table 2 is assumption)</li>
<li>Actual tank dimensions &amp; weld layout (non-public → representative-value validity)</li>
<li>GW frequency band &amp; sensor placement (transferability of fairing settings)</li>
<li>Coupling order of pressure × cryo × fatigue (analysis-step design)</li>
<li>Material-model swap scope for the future CFRP cryotank</li>
</ul>
</section>

<footer>
<span>GNN-SHM · Hydrogen Tank SHM — Design Note</span>
<span><a href="index.html">← Roadmap</a> · <a href="https://github.com/keisuke58/Payload_gnn">GitHub</a></span>
</footer>
</div>
<script>
(function(){
var root=document.documentElement, btn=document.getElementById('themeToggle');
function cur(){ if(root.dataset.theme) return root.dataset.theme;
return window.matchMedia('(prefers-color-scheme: dark)').matches?'dark':'light'; }
btn.addEventListener('click',function(){ root.dataset.theme = cur()==='dark' ? 'light' : 'dark'; });
})();
</script>
</body>
</html>
1 change: 1 addition & 0 deletions docs/index.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -311,6 +311,7 @@ <h4>Training</h4>
<h4>sim2real + guarantee</h4>
<p>Bridge ambient test data → cryogenic operation with the existing DA toolkit; wrap leak-risk decisions in split-conformal FPR guarantees.</p></div></div>
</div>
<p style="margin-top:24px"><a href="hydrogen-tank.html" style="display:inline-flex;align-items:center;gap:8px;font-family:ui-monospace,monospace;font-size:14px;font-weight:600;color:var(--cryo);text-decoration:none;border:1px solid color-mix(in srgb,var(--cryo) 45%,transparent);background:color-mix(in srgb,var(--cryo) 8%,transparent);border-radius:8px;padding:11px 18px">Read the full design note →</a></p>
</section>

<div class="decide">
Expand Down
Loading