TY - JOUR T1 - Fatigue life estimation of bolts in flanges of a reinforced cylindrical shell TT - تخمین عمر خستگی پیچ های فلنج اتصالی در یک پوسته استوانه ای تقویت شده JF - mdrsjrns JO - mdrsjrns VL - 14 IS - 13 UR - http://mme.modares.ac.ir/article-15-5808-en.html Y1 - 2015 SP - 201 EP - 208 KW - Fatigue Life KW - Bolt KW - ISO 3800 KW - Reinforced cylindrical shells KW - Shell-to-Solid Sub-modeling N2 - Bolt joints play an important role in the industries, so the estimation of fatigue life of bolts is an essential task. The aim of present study is estimation of fatigue life of connection bolts of two flanges in reinforced cylindrical shell with cutout. Two groups of data are needed for mentioned bolt: fatigue properties of bolt and value of stress of bolt due to applying load to structure. So, two paths have been gone. First, the fatigue properties of bolt have been measured in laboratory according to ISO 3800 standard. For this purpose a specific fixture was designed and manufactured which provided testing different bolts. By doing fatigue experiments, the fatigue properties of mentioned bolt such as fatigue limit and Basquin’s equation constants (fatigue strength coefficient and fatigue strength exponent) have been measured. Fracture mechanism and fracture surface have been investigated, too. Afterward, in the next step the value of stress in bolt that is subjected to mix loading has been calculated by using of FE modeling. Because of problem complexities, cost of three dimensional analysis of this problem increases, so analysis of the problem has been performed by shell-to-solid sub-modeling technique. At the end, by calculating the nominal stress of bolt from FE modeling and using fatigue properties witch obtained from experiments, life of the mentioned bolt has been estimated. M3 ER -