TY - JOUR T1 - Theoretical and experimental investigation of notch effect on fatigue life of cylindrical HSLA100 steel specimens in rotating bending load TT - مطالعه تحلیلی و تجربی اثر فاق بر عمر خستگی نمونه‌های استوانه‌ای فولاد HSLA100 در بارگذاری خمشی چرخان JF - mdrsjrns JO - mdrsjrns VL - 15 IS - 12 UR - http://mme.modares.ac.ir/article-15-4205-en.html Y1 - 2016 SP - 113 EP - 120 KW - HSLA100 KW - Fatigue KW - Weakest-link theory KW - strength factor KW - HSLA100 KW - steel N2 - This research investigates notch effect on fatigue life of HSLA100 steel which is widely applicable in the marine industry. Experimental tensile tests and rotating bending fatigue tests were performed on both smooth and notched cylindrical specimens and the corresponding mechanical properties and S-N curves were obtained. To better investigate the notch and also size effect on fatigue life of the specimens, two different notch geometries and specimen dimensions were used. To calculate the fatigue strength factor, stress distribution under bending load is simulated for smooth and notched specimens. Then, the stress distribution under bending load is converted to stress distribution under rotating bending load using an in-house developed code. Finally, using an in-house developed code, the fatigue strength factor of the specimens is calculated by weakest link theory. In order to better investigate the weakest-link theory, in calculating the fatigue strength factor, this factor is calculated from the classical methods and compared with experimental results. Finally, Comparison of theoretical with experimental results shows that the weakest-link theory gives better predictions than other classical methods and the results are closer to experimental ones. Also, Weakest-link theory uses the finite element results to predict notch effect. This facilitates the use of this theory in fatigue design of complicated specimens. M3 ER -