📋 Case Study

Composite Materials for Wind Turbines

Galvanic corrosion at composite-metal interface due to seawater ingress and cathodic disbondment of adhesive

🏗️ Project Overview

Offshore wind turbine tower transition piece (carbon fiber/epoxy composite bonded to S32750 super duplex flange)

🎯 Challenge

Galvanic corrosion at composite-metal interface due to seawater ingress and cathodic disbondment of adhesive

🔧 Design Approach

Three-layer isolation: epoxy primer + glass flake barrier coat + dielectric gasket; qualified per ASTM D1141 synthetic seawater immersion + cyclic salt fog

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

Galvanic Current at Interface

I = σ × ΔE / t

Result: 0.03 µA/cm²

Below threshold for adhesive hydrolysis per ASTM D883

Bondline Chloride Threshold

Fickian diffusion model

Result: <15 ppm Cl⁻ at 10 yr

Predicted via COMSOL Multiphysics® corrosion module

📊 Results

No bond degradation observed after 7 years in Dogger Bank conditions; 99.2% operational availability

💡 Lessons Learned

• •Adhesive selection must include ion-blocking fillers (e.g., surface-treated alumina)
• •Interface geometry (e.g., tapered joint) reduces capillary ingress by 60%

✅ Key Takeaways

• 1Adhesive selection must include ion-blocking fillers (e.g., surface-treated alumina)
• 2Interface geometry (e.g., tapered joint) reduces capillary ingress by 60%