Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 10 2018 12 27 Experimental Investigation of Fatigue Damage Development Using Microhardness and Chord Modulus Variation Methods in Stainless Steel 316L Experimental Investigation of Fatigue Damage Development Using Microhardness and Chord Modulus Variation Methods in Stainless Steel 316L 2679 2690 3213 10.22060/mej.2018.14748.5933 FA Meysam Kalhor Department of mechanical engineering, university of tehran, iran Seyed Mahdi Ganjiani 0000-0001-9839-7795 Arsalan Azami Department of mechanical engineering, University of tehran, Tehran, Iran Journal Article 2018 07 28 In this research, an experimental study of the fatigue damage growth process has been investigated for 316L stainless steel. For this purpose, using ASTM E466 fatigue special standard, testing samples with rectangular cross-section, has been drawn and prepared. The mechanical properties of the material were extracted through the test. Uniaxial low cycle fatigue has been performed at similar stress amplitudes, similar frequency, and various loading cycles. After carrying out fatigue tests, in order to derivation damage development process, microhardness and loading-unloading tests –deriving relation of microhardness and chord modulus with strain- has been performed too. Experimental tests have been carried out under environmental conditions. The Damage development process was achieved, using results of fatigue, loading-unloading, and microhardness tests. A method for estimating damage is proposed in this research. In the end, the results of the methods of the chord modulus, microhardness and purposed are compared with each other. The damage growth process of the purposed method has a good fit with the method of chord modulus. The obtained critical damage was 0.38 by using the chord modulus method and 0.41, by microhardness In this research, an experimental study of the fatigue damage growth process has been investigated for 316L stainless steel. For this purpose, using ASTM E466 fatigue special standard, testing samples with rectangular cross-section, has been drawn and prepared. The mechanical properties of the material were extracted through the test. Uniaxial low cycle fatigue has been performed at similar stress amplitudes, similar frequency, and various loading cycles. After carrying out fatigue tests, in order to derivation damage development process, microhardness and loading-unloading tests –deriving relation of microhardness and chord modulus with strain- has been performed too. Experimental tests have been carried out under environmental conditions. The Damage development process was achieved, using results of fatigue, loading-unloading, and microhardness tests. A method for estimating damage is proposed in this research. In the end, the results of the methods of the chord modulus, microhardness and purposed are compared with each other. The damage growth process of the purposed method has a good fit with the method of chord modulus. The obtained critical damage was 0.38 by using the chord modulus method and 0.41, by microhardness https://mej.aut.ac.ir/article_3213_42d19a69f43b9e0d4882f28aeb411fef.pdf