Analysis and test of generality of C-T curve

To analyze the generality of C-T curve of pre-corrosion factor (C) versus corrosion time (T), the method of comparing C value or comparing parameters of C-T curves is proposed, and the weak-correlation of C-T curve with fatigue load spectrum, stress level and crack size are gained from the testing result. C is the ratio of pre-corrosion fatigue life to non-corrosion fatigue life, and C-T curve is the basis of evaluating the fatigue life for aircraft structure in corrosive environment. To decrease the task for testing the C-T curve, two methods are used to analyze the correlation of C-T curve and the factors, such as fatigue load spectrum, stress level and crack size, and the generality is proved by the pre-corroded fatigue life of the same specimen under similar spectra, constant-stress levels, and different crack sizes. The fatigue test is performed under the spectrum and constant amplitude loading, and the same conclusion is obtained, so the generality is gained.