Sultan wrote:
The issue is that those who claim vibration monitoring is superior to, or can eliminate, debris monitoring border on delusional. It is only a great addition to the tool kit. For vibration to be generated you have to have an actionable level of damage. Problem with cracks on high stress gears are that they may propogate to a critical level before any loss of stiffness is noticed in a daily check of HUMS. It is basically good, good and bang.
To detect a crack the only concept I can see as practicable would be a delta resistance detection system of some kind. (thermal or magnetic resonance imaging being cited as too costly above). Strain and stress guages have been around for a long time. In simple terms I envisage a system that runs a current through the gearbox from entry to exit and gives a resistance level readout which would have a known behavioural pattern for load/torque/temp settings. A crack or significant fatigue (chip loss)would hopefully give a warning fractionally in advance of chip /temp/pressure warning systems.
Does anyone know of such a system?
The added benefit of such a system is that it may be applied in non magnetic material systems.. as long as they conduct a current. (Ceramics can be made conductive or not as required.. I believe.