Rotating Fatigue Machine
- A bench mounted machine for demonstrating the failure of materials when subjected to an alternating stress, showing both low and high cycle fatigue.This reduces set up time and unwanted vibration.
- A variable speed drive controls the motor to allow safe and gradual increase of the cycle rate.
- The motor turns a compliant coupling and a precision shaft held in sturdy bearings.
- A collet type chuck on the end of the shaft grips the specimen with reliable and accurate concentricity.
- A gimbal mounted self-aligning bearing holds the ‘free end’ of the specimen.
- The gimbal assembly links to a short load arm. A load cell links the short load arm to a longer load arm.
- Applies a purely vertical load even when the specimen deflects under load.
- The longer load arm has an integral moveable dead weight that sets the load.
- Load cell measures the load and an electronic sensor measures shaft rotation.
- The separate control and instrumentation unit shows the load, speed (cycle rate) and the number of cycles.
- The specimens have a special design that creates a point of maximum stress at their midpoint rather than at their end.