Inhaltsangabe: Abstract: The suitability of different materials for the tuning structure of the LHC rf cavities is evaluated. The structure spanning the temperature interval from room to cryogenic is subjected to mechanical loading, and radiation. A filament wound tube reinforced with high-strength carbon fibres is considered to be most appropriate. Design calculations are performed using laminate theory. The safety margin for a cylindric filament wound tube under the given mechanical and thermal loading conditions is calculated for different winding angles. The calculations indicate that the...