Master of Science in Mechanical Engineering (MSME)
The effect of prior corrosion fatigue damage on the thermographic response of 1018 low carbon steel is investigated. Specimens were subject to rotating bending fatigue at 38 Hz loading frequency while being exposed to a 3.5% NaCl and distilled water solution. Some specimens were subject to corrosion fatigue for part of their fatigue life and then their thermographic response measured under fatigue in air at 62 Hz loading frequency. Fatigue tests in air with thermographic measurement were performed as a comparison. It was observed that the initial temperature rise after corrosion fatigue fits the previously proposed model for air fatigue, N_f=c_1 R_θ^(c_2 ). The constants c_1 and c_2 were determined to be 11,110 and -0.7, respectively, for fatigue in air and fatigue following corrosion fatigue. Using a statistical analysis method, a lower bound conservative fatigue life prediction methodology is proposed to estimate the minimum remaining life for a given R_θ value. Verification tests were performed, with conservative fatigue life predictions given in every case.
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Purvis, Richard Wayne, "An Experimental Investigation of Corrosion Fatigue Life via Thermographic Method" (2014). LSU Master's Theses. 3880.