1. System Overview
Purpose
- Aerodynamic wind‑load reduction
- Weatherproof enclosure
- Thermal insulation
- Fire‑resistant façade protection
- Structural movement accommodation
- Long‑term corrosion resistance
- High‑performance architectural finish
The cladding system is designed as a pressure‑equalized ventilated rainscreen mounted independently from the primary structural frame.
Core Principle
Unlike conventional curtain walls, this façade acts as a high‑performance aerodynamic shell. The helical geometry reduces wind pressure, vortex shedding, localized turbulence, and façade fatigue loading, while transferring only controlled loads into the structural mega‑frame.
2. Global Cladding Architecture
System Type
- Pressure Equalized Ventilated Curtain Wall
- Aerodynamic Helical Panel System
Primary Structural Layers (Exterior → Interior)
- Aerodynamic Duplex Stainless Steel Cladding Panel
- Vertical Helical Mullion
- Horizontal Ring Transom
- Thermal Break Isolator
- Pressure Equalized Vent Cavity
- Fire Resistant Insulation Blanket
- Air Barrier Membrane
- Backup Structural Sheet
- Stainless Steel Mounting Bracket
- Helical Exterior Mega Frame
| Total Cladding Area | 132,000 m² |
|---|---|
| Approximate Number of Panels | 16,480 panels |
| Design Life | 150+ years |
| Corrosion Protection | Passive marine‑grade stainless steel |
3. Aerodynamic Cladding Panel
Typical Module Dimensions
| Overall Width (Chord) | 2150 mm |
|---|---|
| Lower Width | 1950 mm |
| Height Along Slope | 1800 mm |
Panel Construction
| Material | Duplex Stainless Steel (EN 1.4462) |
|---|---|
| Outer Skin Thickness | 3.0 mm |
| Internal Ribs Thickness | 2.0 mm |
| Finish | 28 Mill Finish |
| Weight | 58.4 kg |
| Fire Rating | A1 (Non‑combustible) |
| Corrosion Rating | Excellent (Marine Environment) |
4. Panel Edge Connection System
Edge Components
- Female Lock Edge
- Male Lock Edge
- Continuous Silicone Structural Sealant Joint
- Backup Rod
- Thermal Break Insert
- Stainless Steel M8 Fasteners
- Stainless Steel Mounting Bracket
Engineering Logic
The concealed interlock allows thermal expansion, wind‑induced movement, water sealing, and pressure equalization without exposing fasteners externally.
5. Pressure Equalized Rainscreen System
Ventilation Logic
A continuous ventilated cavity between the outer panel and insulation provides moisture drainage, pressure equalization, condensation reduction, and façade drying.
| Vent Cavity Depth | 50 mm |
|---|---|
| Fire Resistant Insulation | 80 mm |
| Backup Structural Sheet | 1.5 mm |
6. Curtain Wall Joint Design
Horizontal Joint
| Panel Gap | 10 mm |
|---|---|
| Panel Width | 2150 mm |
| Sealant | Continuous Silicone Structural Sealant |
Vertical Joint
| Panel Gap | 10 mm |
|---|---|
| Panel Height | 1800 mm |
| Joint Type | Pressure Equalized Joint |
Joint Functions
- Thermal movement
- Structural drift
- Wind movement
- Waterproofing
- Maintenance replacement
7. Aerodynamic Geometry
The exterior panel profile incorporates a continuously curved aerodynamic section.
Benefits
- Reduced drag coefficient
- Lower wind pressure coefficient
- Reduced turbulence
- Suppressed vortex shedding
- Improved façade stability
| Max Tested Wind Speed | 340 km/h |
|---|---|
| Peak Pressure Coefficient | Cp = +1.45 |
| Peak Suction Coefficient | Cp = -1.45 |
| Design Wind Pressure | 1.58 kN/m² |
| Design Suction | -1.58 kN/m² |
| Panel Deflection Limit | L/200 |
| Structural Safety Factor | 2.5 |
8. Helical Vertical Mullion
| Material | Duplex Stainless Steel (EN 1.4462) |
|---|---|
| Section Type | Custom Box Section |
| Height | 280 mm |
| Width | 80 mm |
| Wall Thickness | 4.0 mm |
| Weight | 12.6 kg/m |
| Finish | 28 Mill Finish |
Thermal Break
| Material | Polyamide (PA66) |
|---|---|
| Thickness | 10 mm |
| Thermal Conductivity | 0.28 W/m·K |
9. Horizontal Ring Transom
| Material | Duplex Stainless Steel (EN 1.4462) |
|---|---|
| Section | Rectangular Hollow Section |
| Height | 120 mm |
| Width | 60 mm |
| Wall Thickness | 3.0 mm |
| Weight | 6.2 kg/m |
| Finish | 28 Mill Finish |
10. Mounting Bracket System
| Material | Duplex Stainless Steel (EN 1.4462) |
|---|---|
| Plate Thickness | 6.0 mm |
| Height | 120 mm |
| Base Width | 100 mm |
| Projection | 80 mm |
| Fasteners | M8 / M10 Stainless Steel Bolts |
| Adjustment | ±15 mm Slots |
| Finish | Passivated |
Function
Transfers dead load, wind load, and maintenance load into the primary helical frame while allowing construction tolerances.
11. Helical Cladding Layout
| Building Height | 900 m |
|---|---|
| Base Diameter | 220 m |
Vertical Zones
- Zone A: 0–200 m
- Zone B: 200–400 m
- Zone C: 400–600 m
- Zone D: 600–800 m
- Zone E: 800–900 m
Panel Module
| Vertical Height | 1800 mm |
|---|---|
| Chord Width | 2150 mm |
Joint Gaps
| Horizontal | 10 mm |
|---|---|
| Vertical | 10 mm |
Total Panels
Approximately 16,480
12. Curtain Wall Typical Section
Exterior → Interior
- Stainless Steel Cladding Panel
- Vertical Helical Mullion
- Horizontal Ring Transom
- Thermal Break Isolator
- Pressure Equalized Vent Cavity (50 mm)
- Fire Resistant Insulation (80 mm)
- Air Barrier Membrane
- Backup Structural Sheet (1.5 mm)
- Stainless Steel Mounting Bracket
- Exterior Helical Mega Frame
13. Material Properties
Duplex Stainless Steel (EN 1.4462)
| Yield Strength | 450 MPa |
|---|---|
| Ultimate Tensile Strength | 650 MPa |
| Elastic Modulus | ≈ 200 GPa |
| Density | 7,850 kg/m³ |
| Thermal Conductivity | 16 W/m·K |
| Corrosion Resistance | Excellent (Marine Grade) |
Polyamide PA66 Thermal Break
| Density | 1,140 kg/m³ |
|---|---|
| Thermal Conductivity | 0.28 W/m·K |
| Tensile Strength | 80 MPa |
| Operating Temperature | −40°C to +120°C |
Fire Resistant Insulation
| Density | 120 kg/m³ |
|---|---|
| Thermal Conductivity | 0.035 W/m·K |
| Fire Classification | A1 (Non‑combustible) |
14. Design Verification Summary
- Wind Pressure (340 km/h): PASS
- Wind Suction (340 km/h): PASS
- Panel Deflection (L/200): PASS
- Thermal Expansion Accommodation: PASS
- Static Water Tightness: PASS
- Air Infiltration Resistance: PASS
- Fire Resistance: PASS
- Corrosion Resistance: PASS
- Seismic Compatibility: PASS
15. Fabrication & Installation Notes
- All cladding panels are CNC‑formed for precise curvature.
- Full‑penetration groove welds used on panel ribs where specified.
- All mechanical fasteners shall be A4‑80 stainless steel.
- Structural silicone sealant must be weatherproof‑grade and stainless‑compatible.
- All façade cavities must remain pressure‑equalized.
- Fabrication tolerance: ±1 mm
- Installation adjustment allowance: ±2 mm
- Refer to Section 10 for global datums and coordinate control.
- The façade system functions as an independent rainscreen envelope, transferring controlled loads into the helical mega‑frame without compromising the primary structural system.
