A study on the free vibration analysis of stiffened laminated composite cylindrical shell is described in this paper. The eight-noded isoparametric degenerated shell element is developed to model both shell panel and stiffeners by using the degenerated solid concept based on ReissnerMindlin assumptions which taking into account the shear deformation and rotatory effect. | Journal of Science and Technology 54 (5) (2016) 771-784 DOI: FREE VIBRATION ANALYSIS OF LAMINATED STIFFENED CYLINDRICAL PANELS USING FINITE ELEMENT METHOD Trinh Anh Tuan1, Tran Huu Quoc2, Tran Minh Tu2, * 1 2 HSE Training and Design Consultancy Company Limited, 36B, 51 Lane, Doc Ngu Str., Ba Dinh Dist., Hanoi University of Civil Engineering, 55 Giai Phong Road, Hai Ba Trưng District, Ha Noi * Email: tpnt2002@ Received: 20 April 2016; Accepted for publication: 20 September 2016 ABSTRACT A study on the free vibration analysis of stiffened laminated composite cylindrical shell is described in this paper. The eight-noded isoparametric degenerated shell element is developed to model both shell panel and stiffeners by using the degenerated solid concept based on ReissnerMindlin assumptions which taking into account the shear deformation and rotatory effect. Numerical results are presented and comparison is made with the published results from the literature and the good agreement is found. Parametric studies considering different geometrical variables of shell and stiffeners have also been carried out. Keywords: laminated composite shells; stiffened shells; vibration analysis; finite elements; degenerated shell element; static analysis. 1. INTRODUCTION Laminated composite shells and particularly cylindrical panels are increasingly used in many engineering applications such as aerospace, mechanical, civil and marine engineering structures. The cylindrical panels are often stiffened by stiffener and ring to enhance the specific strength/stiffness to weight ratio of the structure. The vibration characteristics of stiffened cylindrical panels are of considerable importance to mechanical and structural engineers. Vibration of cylindrical shells has been extensively studied by many researchers. The vibration analysis of shell is presented in work done by Leissa [1], and Soedel [2]. Quatu [3] studied vibration of laminated composite .
