| 摘要 |
A method of forming a composite acoustic panel (26). The method begins by arranging a perforated sheet (54) on a convex lay-up mandrel (70), arranging a core material (62, 74) on the perforated sheet (54), and curing the perforated sheet (54) and the core material (62, 74) to form a composite acoustic core (60) having a lay-up mandrel side and an opposite upper side. Composite sheets (96, 98) are then arranged on a concave lay-tip mandrel. The composite acoustic core (60) is arranged on the composite sheets (96, 98) with the opposite upper side of the acoustic core (60) against the composite sheets (96, 98). The composite acoustic core (60) and the composite sheets (96, 98) are then cured so as to form the acoustic panel (26). A sacrificial sheet (76) can be added to upper side of the core material (62, 74) prior to curing the perforated sheet (54) and the core material (62, 74). The sacrificial sheet (76) preferably has a low coefficient of thermal expansion. The sacrificial sheet (76) is machined off as the upper side of the core material (62, 74) is shaped. The use of the sacrificial sheet (76) permits the acoustic core (60) to maintain its shape during curing without warpage from residual thermal stresses (R) . The perforated sheet (50) thus maintains a contour that is substantially matched to the outer surface of the convex lay-up mandrel (70). <IMAGE> |
