This paper presents some numerical results of bending and vibration analyses of an unstiffened and stiffened folded laminate composite plate using finite element method. The effects of fiber orientations, boundary conditions, stiffener conditions of the plates for deflections, natural frequencies, and the corresponding mode shapes, transient displacement responses were considered. | Vietnam Journal of Mechanics, VAST, Vol. 35, No. 1 (2013), pp. 31 – 50 STATIC AND DYNAMIC ANALYSES OF STIFFENED FOLDED LAMINATE COMPOSITE PLATE Tran Ich Thinh1 , Bui Van Binh2 , Tran Minh Tu3 1 Hanoi University of Science and Technology, Vietnam 2 University of Power Electric, Vietnam 3 University of Civil Engineering, Vietnam Abstract. This paper presents some numerical results of bending and vibration analyses of an unstiffened and stiffened folded laminate composite plate using finite element method. The effects of fiber orientations, boundary conditions, stiffener conditions of the plates for deflections, natural frequencies, and the corresponding mode shapes, transient displacement responses were considered. The Matlab programming using rectangular isoparametric plate element with five degree of freedom per node based on Mindlin plate theory was built to solve the problems. A good agreement is found between the results of this technique and other published results available in the literature. Keywords: Bending, folded laminated composite plate, vibration, dynamic response, stiffeners, stiffened folded laminated composite plate, finite element. 1. INTRODUCTION Many stiffened flat plates are designed to resist vibration due to dynamical loads. The effect of the stiffeners on the vibration behaviors of flat plates is known to be significant. Thus it is not surprising that a number of papers has been devoted to the study of this problem. Because the laminated plates with stiffeners become more and more important in the aerospace industry and other modern engineering fields, wide attention has been paid on the experimental, theoretical and numerical analysis for the static and dynamic problems of such structures in recent years. Turkmen and Mecitoglu [1] presented a numerical analysis and experimental study of stiffened laminated flat plates exposed to blast shock waves. Zhao et al. [2] using an energy approach, investigated the free vibration of the stiffened
