محاسبه بار بحراني و مد كمانش پوسته هاي استوانه اي با تقويت كننده هاي حلقوي به روش اجزاء محدود

In this article critical load and mode shape of buckling for ring-stiffened cylindrical shells under external pressure are determined on the base of total strain potential energy of structure by using the Trefftz critrion. Assumption of orthotropic behavior of structure is used in obtaining constitutive equations. The geometric nonlinearity used here is limited to what may be called an intermediate class of deformations. The displacement method is used for structural analysis. Finally, the accuracy of the results of the software is compared with the experimental data.