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AIRBORNE FLUTTER EXCITATION SYSTEM
The AFES is an electro-hydraulic inertial exciter system capable of creating controlled sinusoidal forces up to 400 lbs (1780 N) over a frequency range of 3 Hz to 15 Hz. Force is generated by the acceleration of a 250 lb (114 kg) mass by a hydraulic exciter with a 4 inch (100 mm) maximum stroke and a 600 lb (2670 N) force capability. The actuator is controlled by a dual loop controller which maintains the mass oscillating about a center position by monitoring an LVDT. while peak force is compressor controlled by monitoring the exciter’s strain gage load cell. The actuator is powered by a 3000 PSI (206 E5 Pascal), 5 GPM (20 lpm) hydraulic power supply.
The complete AFES is powered by an aircraft’s 400 Hz 125 v 3 phase power system and 50/60 Hz 120/240 v power system. System inputs consist of 28 V relay hydraulic start / stop and 1.0 V sinusoidal output from an external signal source. The system supports dwells and sine sweep testing with rates from 0.1 to 3.0 octaves per minute.
The complete system has been qualified by Wyle Laboratories, Huntsville, AL, to meet MIL-STD-810F for Rapid Decompression, Temperature, Pressure, Random vibration, and Minimum Structural Integrity Test. Calculations verified compliance with Ultimate Load Factors of 6 g (up), 12 g (down) 3.5 g (lateral) and 2 g (fore and aft) and Survivable Crash Loads of 16 g (forward).
Wyle Laboratories has certified the AEFS to MIL-STD-461E for control of Electromagnetic Interface Characteristics of Subsystems & Equipment in compliance with:
- CE101 and CE102 Conducted Emissions
- CS114 Conducted Susceptibility
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- RE101 and RE102 Radiated Emissions
- RS103 Radiated Susceptibility
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MASS CARRIAGE ASSEMBLY WITH EXCITER AND 250 lb (114 kg) PROOF MASS
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Photo shows the Mass Carriage Assembly with the Exciter installed on an inertial test pad. In the application, the Mass Carriage Assembly with linear roller bearings was supplied by the customer and the combined system was subjected to all MIL-STD-810F environmental tests. |
EXCITER HEAD
Stroke |
Force |
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Servo Valve |
LVDT |
Load Cell |
Dimensions |
Weight |
Hydraulic Oil |
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| 4 in (100 mm) |
| 600 lb (2670 N) (Hydraulic Power Supply set to 138 E5 Pascal) |
| 1000 lb (4450 N) (Hydraulic Power Supply set to 206 E5 Pascal) |
| 5 GPM (20 lpm) |
| 4 in (100 mm) |
| Strain Gage 5000 lb (22,000 N) |
| 19 in (475 mm) (length); 4 in (100 mm) (overall diameter) |
| 42 lb (19 kg) |
| Mil-H-83282 |
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MASTER CONTROLLER
Static Control Loop |
Dynamic Control Loop
a |
| Input Sensitivity |
Output Sensitivity of Load Cell |
Sweep Rate |
Power |
Dimensions |
Weight |
Inputs |
| Outputs |
| Meters |
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| Maintains midpoint of exciter piston at 50 mm |
Maintains constant dynamic peak force at user defined levels
during sweeps and dwells (compression control) |
| 1.0 v peak sine =1780 N (linear from 0.1 v to 1.0 v) |
| 250 lb/v (1112 N/v) |
| 0.1 to 3.0 Octave/minute |
| 120/240 v 50/50 Hz (from Hydraulic Power Supply) |
| 14.6 in (175 mm) (Height); 19 in (475 mm) (Width); 25 in (575 mm) (Depth) |
| 53 lb (24 Kg) |
| Load Cell, LVDT, Signal Source |
| Force, Displacement |
| Force, Displacement |
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HYDRAULIC POWER SUPPLY
Max Pressure |
Max Flow |
| Reservoir Capacity |
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Power |
| Start/ Stop |
Pilot Emergency Stop |
Automatic Shutdown and Indicators |
Indicators |
Dimensions |
Weight |
| Overall SPL |
| Pump |
| Cabinet Attachment Points |
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| 3000 PSI (206 E5 Pascal) |
| 5 GPM (20 lpm) |
| 8 GAL (32 l sealed) |
| Air/Oil Heat Exchanger |
| 400 Hz 125 v 3 phase; 50/60 Hz 120/240 v single phase |
| 28 v relay power |
| 28 v relay power |
| Over Temperature; Low Oil Level; Oil Reservoir Over Pressure |
| Phase Correct; Blocked Oil Filter; Motor Power Applied |
| 31.5 in (800 mm) (Height); 32.9 in (835 mm) (Width); 49.2 in (1250 mm) (Length) |
| 950 lb (432 kg) |
| < 90 dB |
| Variable Volume Pressure; Compensated MotorPump |
| Aircraft Seat Rails |
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