| 摘要 |
The precursor comprises structural fibres 24 embedded in a cured matrix 26 interposed between removable plies 20, and a sacrificial fibre 28 extending through the removable plies 20, the matrix material 26 and the structural fibres 24. The sacrificial fibres 28 are removed from the precursor after removing the removable plies 20 to form a through hole in the precursor at a location of the sacrificial fibre 28. The sacrificial fibre 28 is preferably water soluble and coated with a protective substance. The removable plies 20 are preferably polytetrafluoroethylene (PTFE) coated fibreglass. The composite is used for acoustic attenuation for aeroplanes. |
