Comparison of two non-destructive inspection techniques on the basis of sensitivity and reliability

Two non-destructive inspection (NDI) methods have been used to determine the damage tolerance life prediction of aero-engine turbine discs. For this purpose, low cycle fatigue cracks were examined in the compressor discs of tie bolt holes. The successful implementation of damage tolerance design method strongly depends on the sensitivity and reliability of applied NDI method.The result of this study indicated that the manual eddy current inspection method is more sensitive and more reliable than the liquid penetrant inspection method in terms of detection of small cracks in the compressor discs.