Nonlinear Buckling numerical Analysis of stiffened cylindrical shell with initial imperfection

Journal of Mechanical Research and Application

دوره 11، شماره 1، شهریور 2021، صفحه 49-71   

نویسندگان

amirreza shahani¹؛ fatemeh feghhi^{* 2}

¹Department of Applied Mechanics Faculty of Mechanical Engineering, K.N.T. University of Technology. Tehran. Iran

²mechanical engineering. khaje nasir university of technology

چکیده

In this paper, the buckling behavior of stiffened cylindrical shells with initial imperfection under axial loading is numerically studied. The Riks method was used to obtain the nonlinear buckling load and the load-displacement curve. The effect of longitudinal and circumferential stiffeners (stringers and ribs ) was studied on the buckling load as the stiffeners were used separately and together. Also, by considering the shape modes of linear buckling as the initial imperfection, the nonlinear buckling and the sensitivity of the shell to the initial geometric imperfection and its size was investigated.
Finally, the using of stiffeners, and the existence of imperfection and their effect on buckling load are presented.
It has been observed that the addition of stringer and rib can significantly increase the buckling load, and improve resistance reduction which geometric imperfection caused. As important result, The effect of rib reinforcement does not decrease with increasing initial geometric imperfection, while with increasing geometric imperfection, the effect of string reinforcement decreases. Also, the Snap-Back points observed in the load- displacement curve, indicate the local buckling happened in the shell, during that the strength of the shell is reduced, but the shell still has the ability to withstand under the load and the structure does not fail