Carbon Fiber Tube Interface Design Skills: How to Avoid Stress Concentration During Installation?

Carbon fiber’s Achilles’ heel is its vulnerability to stress concentrations—sharp corners, abrupt diameter changes, or overtightened clamps can trigger delamination or fiber fracture. Intelligent interface design mitigates these risks.
Key Principles:
Fillets Over Sharp Edges: Use radiused transitions (≥1.5× wall thickness) at joints.
Load Distribution: Employ bonded doublers or carbon fiber washers under bolt heads to spread clamping force.
Avoid Drilling Near Ends: Holes within 2× OD of tube termini drastically reduce compressive strength. Prefer adhesive bonding or external sleeves.
Use Compliant Interlayers: Silicone or urethane pads between carbon and metal prevent galvanic corrosion and cushion dynamic loads.
In modular systems, design slip-fit interfaces with interference tolerances of 0.02–0.05 mm, secured with structural epoxy—not screws alone. For threaded connections, always embed metal inserts during curing; never tap directly into CFRP.
Remember: carbon fiber excels in distributed, axial loads—not localized punctures. Design accordingly.
@loongcarbonfiber