OICC Press Journal of Solid Mechanics 2008-7683 11 1 2019 03 30 Experimental and Numerical Free Vibration Analysis of Hybrid Stiffened Fiber Metal Laminated Circular Cylindrical Shell 105 119 EN A Nazari Department of Aerospace Engineering, Aerospace Research Institute, Tehran, Iran K Malekzadeh MalekAshtar University, Tehran, Iran A.A Naderi Faculty of Mechanical Engineering, Emam Ali University, Tehran, Iran Journal Article 2019 03 30 The modal testing has proven to be an effective and non-destructive test method for estimation of the dynamic stiffness and damping constant. The aim of the present paper is to investigate the modal response of stiffened Fiber Metal Laminated (FML) circular cylindrical shells using experimental and numerical techniques. For this purpose, three types of FML-stiffened shells are fabricated by a specially-designed method and the burning examination is used to determine the mechanical properties of them. Then, modal tests are conducted to investigate the vibration and damping characteristics of the FML-stiffened shells. A 3D finite element model is built using ABAQUS software to predict the modal characteristics of the FML-stiffened circular cylindrical shells with free-free ends. Finally, the achievements from the numerical and experimental analyses are compared with each other and good agreement has been obtained. Modal analyses of the FML-stiffened circular cylindrical shells are investigated for the first time in this paper. Thus, the results obtained from this study are novel and can be used as a benchmark for further studies.