Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 54 8 2022 10 23 Study of Autofrettage Process Effect in Thick-walled Cylinder with Metal Matrix Composite by the method of Finite Element Cyclic Stress Analysis Study of Autofrettage Process Effect in Thick-walled Cylinder with Metal Matrix Composite by the method of Finite Element Cyclic Stress Analysis 1867 1894 4865 10.22060/mej.2022.20983.7353 FA Hassan Sayar Semnan University Ramin Molahamzezadeh Islamic Azad University Mohammad Hossein Korani Islamic Azad University Mohammad Azadi سمنان-مهندسی مکانیک 0000-0001-8686-8705 Journal Article 2022 01 11 The goal of this study is to analyze the interplay of mechanical and thermal properties and the applied thermomechanical cyclic load combined with the fatigue crack numerical simulation of a thick cylinder. The applied boundary conditions are similar to the working gun barrel during continuous firing. Four stress conditions in 25-950°C and 100-400 MPa pressure has been investigated. Conditions include first, without autofrettage and cracking; second, with autofrettage and without cracking; third, without autofrettage and with cracking; and fourth with autofrettage and with cracking has been investigated. A comparison of the results obtained from simulated models of the autofrettaged and non-autofrettaged barrels has information about the evolution of strains and stresses in the barrel at different points under thermo-mechanical loading cycles in both cases. The materials in the barrel were ST50 steel and SiC/Ti-24Al-11Nb metal matrix composite in three different diameter ratios. The results showed that autofrettage softened the inner surface of the barrel. This phenomenon was seen as a decrease in the hardness of the inner surface of the barrel. The maximum stress of thermomechanical cyclic loading there was until 9 mm of depth. This depth is the active length of crack propagation. The goal of this study is to analyze the interplay of mechanical and thermal properties and the applied thermomechanical cyclic load combined with the fatigue crack numerical simulation of a thick cylinder. The applied boundary conditions are similar to the working gun barrel during continuous firing. Four stress conditions in 25-950°C and 100-400 MPa pressure has been investigated. Conditions include first, without autofrettage and cracking; second, with autofrettage and without cracking; third, without autofrettage and with cracking; and fourth with autofrettage and with cracking has been investigated. A comparison of the results obtained from simulated models of the autofrettaged and non-autofrettaged barrels has information about the evolution of strains and stresses in the barrel at different points under thermo-mechanical loading cycles in both cases. The materials in the barrel were ST50 steel and SiC/Ti-24Al-11Nb metal matrix composite in three different diameter ratios. The results showed that autofrettage softened the inner surface of the barrel. This phenomenon was seen as a decrease in the hardness of the inner surface of the barrel. The maximum stress of thermomechanical cyclic loading there was until 9 mm of depth. This depth is the active length of crack propagation. https://mej.aut.ac.ir/article_4865_d91caca74114d81fdfc578fca82f8d72.pdf