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Helicopter takes to the skies with composite blades
Applications news
Helicopter takes to the skies with composite blades THE AGUSTAWESTLAND EH101 helicopter has completed its first test flight equipped with composite blades incorporating ROHACELL® structural foam, produced by Degussa’s High Performance Polymers business. The 8.5 m rotor blades were made by the British Experimental Rotor Programme (BERP 4). Polymethacrylimide (PMI) structural foams have been used by AgustaWestland in BERP programmes since the 1990s. The benefits of using PMI foam are reported to include: improved buckling resistance of the thin U-spars used in the blade design; and excellent fatigue behaviour enabling the foams to endure the high dynamic loads to which the rotor blades are exposed. In the manufacturing of the blades, PMI foam cores are
6
REINFORCEDplastics
RP513p4_9.indd 6
used as an ‘active’ mandrel and structural part of the component. This method was developed in the late 1990s by Westland Helicopters and the ROHACELL engineering team. During the closed mould curing process, the thermoelastic behaviour of the foam core provides internal pressure, which is said to perfectly consolidate even massive prepreg layers against the mould surface. In-mould pressures of up to 7 bar (100 psi) can be reached and maintained during the cure cycle, and the desired peak pressure can be changed to precisely meet the gel point of the epoxy prepreg. Degussa GmbH; www.degussa.com ROHACELL; www.rohacell.com AgustaWestland; www.agustawestland.com
The AgustaWestland EH101 helicopter.
March 2007
01/03/2007 08:39:28
Helicopter takes to the skies with composite blades THE AGUSTAWESTLAND EH101 helicopter has completed its first test flight equipped with composite blades incorporating ROHACELL® structural foam, produced by Degussa’s High Performance Polymers business. The 8.5 m rotor blades were made by the British Experimental Rotor Programme (BERP 4). Polymethacrylimide (PMI) structural foams have been used by AgustaWestland in BERP programmes since the 1990s. The benefits of using PMI foam are reported to include: improved buckling resistance of the thin U-spars used in the blade design; and excellent fatigue behaviour enabling the foams to endure the high dynamic loads to which the rotor blades are exposed. In the manufacturing of the blades, PMI foam cores are
6
REINFORCEDplastics
RP513p4_9.indd 6
used as an ‘active’ mandrel and structural part of the component. This method was developed in the late 1990s by Westland Helicopters and the ROHACELL engineering team. During the closed mould curing process, the thermoelastic behaviour of the foam core provides internal pressure, which is said to perfectly consolidate even massive prepreg layers against the mould surface. In-mould pressures of up to 7 bar (100 psi) can be reached and maintained during the cure cycle, and the desired peak pressure can be changed to precisely meet the gel point of the epoxy prepreg. Degussa GmbH; www.degussa.com ROHACELL; www.rohacell.com AgustaWestland; www.agustawestland.com
The AgustaWestland EH101 helicopter.
March 2007
01/03/2007 08:39:28