Laboratory Instruments

Cyclic load fatigue machine

Specifications:

fatigue photo
Fatigue load cell

Name: Pneumatic Cyclic loading machine CF5M (Fatigue machine)
Manufacturer: Pober Industries Co., Waban, MA
Application: Pneumatically driven, 8 single unit medium (×7.86), 2 large five unit assembly (× 21.84), 2 medium five unit assembly (×7.86) and 2 X-small ( or small) five unit assembly (× 1.364 for x-sm and x 2.67 for sm).
Cyclic frequency: 1Hz (common setting)
Loading capacity: 40-2000N

Power Timer setting:

We normally set cycle time as 1 second. At this setting: 10k cycle -- 167 mins (2.7833 hrs) 50k cycle -- 833 mins (13.883 hrs)

fatigue machine timer
Fatigue power timer LE3S

To calculate the power timer setting.
enter the cycles: thousand cycles
cycle time: 1 second   

    Your result will show here.

Use "m" to set number by minute. It is different to M with substroke!


Calculate the pressure to setup experiments:

The load impact is driven by compressed air. The supplied pressure should be 110-120 psi. Use the corrrect regulator to adjust pressure for cyclic loading machine.

Enter the load you need to get:
(N)
Large Unit Medium Unit Small Unit X-small Unit

    Your result will show here.

SOP of cyclic load fatigue

Potential harzard in operation

  • Loud noice. >140dB -- using noise protection headset
  • Moving parts.
  • Compressed gas.
  • Electric shock.

    Preparations

  1. Calculate the timer setting and pressure you need. Identify the load cell you should use.
  2. Check the compress air tubing connection to the proper unit set.
  3. Connect load cell unit to power timer. Only the main unit with timer can perform cyclic loading.
  4. Check the air pressue. The in house compressed air should be 120 psi.
  5. Turn on compressed air and adjust the pressre.
  6. Wear ear protector.
  7. Test about 20 cycles to make sure the pressure is stable and load cells are functional.
  8. Turn off power timer and unit power switch.

    9. Set up specimens

  9. Set the timer.
  10. Mount specimens in the proper fixtures.
  11. Align the fixtues with load cell. The 1/8" position pin at the base should fit the back hole of the fixture.
  12. Make the pusher rod have a good contact on the specimen. If there is gap, first impact may cause failure.
  13. Add water in the fixture containers if necessary.

    14. Testing

  14. Turn on timer and power.
  15. Check the load cell function properly before leaving the lab.
  16. Shut off the door.
  17. After the desired time, remove the fixure and collect your specimens.

    18. Finishing

  18. Shut off compressed air. Turn off power switch.
  19. Clean the unit and bench.
  20. Fill logbook.