In this paper, Donnell＇s shell theory and smeared stiffeners technique are improved to analyze the postbuckling and buckling behaviors of circular cylindrical shells of stiffened thin functionally graded material （...In this paper, Donnell＇s shell theory and smeared stiffeners technique are improved to analyze the postbuckling and buckling behaviors of circular cylindrical shells of stiffened thin functionally graded material （FGM） sandwich under an axial loading on elastic foundations, and the shells are considered in a thermal environment. The shells are stiffened by FGM rings and stringers. A general sigmoid law and a general power law are proposed. Thermal elements of the shells and reinforcement stiffeners are considered. Explicit expressions to find critical loads and postbuckling load-deflection curves are obtained by applying the Galerkin method and choosing the three-term approximate solution of deflection. Numerical results show various effects of temperature, elastic foundation, stiffeners, material and geometrical properties, and the ratio between face sheet thickness and total thickness on the nonlinear behavior of shells.展开更多
A rectangular, singly curved and finite strip element for curved sandwich dynamic analysis is developed. The convergence and speed of the method, the strip element density and the reduction of the degrees of freedom e...A rectangular, singly curved and finite strip element for curved sandwich dynamic analysis is developed. The convergence and speed of the method, the strip element density and the reduction of the degrees of freedom etc . are discussed through free vibration analysis of a honeycomb cylindrical shell pan-el. The results show that the frequencies and modal shapes obtained agree very well with the analytical solutions for the symmetrical honeycomb sandwich under the simply supported end conditions.展开更多
基金Project supported by the Vietnam National Foundation for Science and Technology Development(No.107.02-2015.11)
文摘In this paper, Donnell＇s shell theory and smeared stiffeners technique are improved to analyze the postbuckling and buckling behaviors of circular cylindrical shells of stiffened thin functionally graded material （FGM） sandwich under an axial loading on elastic foundations, and the shells are considered in a thermal environment. The shells are stiffened by FGM rings and stringers. A general sigmoid law and a general power law are proposed. Thermal elements of the shells and reinforcement stiffeners are considered. Explicit expressions to find critical loads and postbuckling load-deflection curves are obtained by applying the Galerkin method and choosing the three-term approximate solution of deflection. Numerical results show various effects of temperature, elastic foundation, stiffeners, material and geometrical properties, and the ratio between face sheet thickness and total thickness on the nonlinear behavior of shells.
文摘A rectangular, singly curved and finite strip element for curved sandwich dynamic analysis is developed. The convergence and speed of the method, the strip element density and the reduction of the degrees of freedom etc . are discussed through free vibration analysis of a honeycomb cylindrical shell pan-el. The results show that the frequencies and modal shapes obtained agree very well with the analytical solutions for the symmetrical honeycomb sandwich under the simply supported end conditions.
