Airborn Flutter Excitation2018-10-12T14:36:00+00:00
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

  • RE101 and RE102 Radiated Emissions

  • RS103 Radiated Susceptibility

Exciter Head
Stroke 4 in (100 mm)
Force 600 lb (2,670 N)
Hydraulic Power Supply set to 138 E5 Pascal
1,000 lb (4,450 N)
Hydraulic Power Supply set to 206 E5 Pascal
Servo Valve 5 GPM (20 lpm)
LVDT 4 in (100 mm)
Load Cell Strain gauge 5,000 lb (22,000 N)
Dimensions 19″ (475 mm) length
4″ (100 mm) overall diameter
Weight 42 lb (19 kg)
Hydraulic Oil Mil-H-83282
Airborne Flutter Exciter Head
Hydraulic Power Supply
Max Pressure 3,000 PSI (206 E5 Pascal)
Max Flow 5 GPM (20 l/m)
Reservoir Capacity 8 Gal (32 I sealed)
Cooling Air/ Oil Heat Exchanger
Power 400 Hz – 125 v – 3 phase;
50/60 Hz – 120/240 v single phase
Start/ Stop 28 v relay power
Pilot Emergency Stop 28 v relay power
Automatic Shutdown & Indicators Over temperature; Low oil level;
Oil reservoir over pressure
Indicators Phase correct; Blocked oil filter;
Motor power applied
Dimensions 31.5″ (800 mm) H x 32.9″ (835 mm) W
x 49.2″ (1,250 mm) L
Weight 950 lb (432 kg)
Overall SPL < 90 dB
Pump Variable volume pressure; Compensated motor pump
Cabinet Attachment Points Aircraft seat rails
Airborne Flutter Hydraulic Power Supply
Master Controller
Static Control Loop Maintains midpoint of Exciter piston at 50 mm
Dynamic Control Loop Maintains constant dynamic peak
force at user defined levels during
sweeps and dwells (compression control)
Input Sensitivity 1.0 v peak sine = 1,780 N
(linear from 0.1 v to 1.0 v)
Output Sensitivity of Load Cell 250 lb/v (1,112 N/v)
Sweep Rate 0.1 to 3.0 Octave/minute
Power 120/240 v – 50/50 Hz
(from Hydraulic Power Supply)
Dimensions 14.6″ (175 mm) H x 19.0″ (475 mm) W
x 25.0″ (575 mm) D
Weight 53 lb (24 kg)
Inputs Load cell, LVDT, Signal source
Outputs Force, Displacement
Meters Force, Displacement
Airborne Flutter Master Controller