Reynolds BEng 24th June 2026
1. Risk Assessment Context
Nuclear containment structures rely on reinforced concrete cylindrical shells where long-term performance depends on composite action between steel reinforcement, concrete, and internal cement-aggregate bond. Current design guidance uses empirical coefficient tables whose original theoretical provenance (Viktor Lewe 1915 thin-shell matrix theory) is not clearly referenced. This creates a potential gap in full visibility of safety factors from first principles. Any incompleteness in the foundational mechanics could affect risk assessments for creep, cracking, degradation, and extreme loading scenarios.
Hazard Rating: Catastrophic (failure of containment).
Current Likelihood: Unknown / unquantified due to the missing reference.
Conservative Approach: Treat as requiring urgent review.
2. Proposed Geometric Contribution
Extending Lewe’s 1915 work by treating the wall as an infinitely thin 2D ring/disc yields ring tension as a circumferential judder wave. This produces an augmented hoop-stress equation:σ_θ = pr/t + M_rot + σ_ring tension with potential for 18–20% material savings and improved post-yield ductility through geometric restoring forces.
3. Falsifiable Experiment Proposal
“Do Lewe Tanks Pulse?”
Test whether a cylindrical shell under external elastic confinement exhibits measurable pulsatile (judder-wave) behaviour as predicted by the geometric model.
Phase 1 – Proof-of-Concept Model (Super-Thin Steel Cylinder)
Model Design
Core shell: Extremely thin steel cylinder (0.1–0.3 mm wall thickness).
Initial support: Temporary rigid internal former holds the cylinder perfectly circular.
External confinement: High-strength elastic bands (150–300 mm wide reinforced rubber or composite) wrapped under controlled high tension in a 3-6-9 harmonic pattern.
Former removal: Once wrapping is complete, the internal former is carefully removed.
The steel shell is now held in perfect cylindrical geometry purely by external elastic confinement and geometric stiffness.
Recommended Scale
Diameter: 1.0 m Height: 1.0–1.2 m
This size is practical for laboratory testing, easy to instrument, and large enough to observe meaningful geometric effects without excessive scaling issues in the initial phase.
Instrumentation & Testing
Strain gauges on shell and elastic bands
Radial displacement sensors
High-speed video and vibration monitoring
Controlled internal pressure (water/air) and low-amplitude external excitation
Success Criteria
Observable periodic radial displacement (pulsation) correlated with applied tension and harmonic wrapping pattern.
Why This Experiment is Powerful
Simple, low-cost, and highly falsifiable.
Directly tests the core geometric mechanism (ring-tension judder wave and dilatancy).
Bypasses concrete material variability in Phase 1.
Builds on established literature on externally confined concrete cylinders while introducing the novel Lewe Disc prediction.
Positive or negative results will both advance knowledge and inform risk assessment for containment structures.
Next Steps
I propose building and testing Phase 1 at the University of South Wales as part of a PhD by Portfolio. Detailed drawings, test protocol, and instrumentation plan can be provided immediately.
I would welcome any expert input on refining this experimental design or identifying potential collaborators.
Ace Consultancy
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