Online monitoring of metal fatigue life

A novel nondestructive testing methodology is proposed for online monitoring health and for in situ determination of the fatigue life of a component. This method only requires the determination of current and voltage consumed by the driving motor during its operation. The efficacy of the proposed method is established by performing a series of bending fatigue experiments over a wide range of operating conditions with specimens made of SS304 and SS321 materials. Results are correlated with those obtained thermographically via an infrared camera. To further establish the utility of the approach, tests were conducted with Aluminum 7075-T6 material that experiences minimal temperature rise and renders the thermographic method inefficient. The results show that the proposed method is effective in monitoring the failure of the specimen accurately and reliably.