Computer Modeling of the Creep Process in Stiffened Shells

A methodology for computer modeling of the buckling process for shell structures, taking into account creep of the material, is presented in this work. A mathematical model of shell deformation, accounting for transverse shears, geometric nonlinearity and presence of stiffeners, is provided. The process of creep is modeled according to a linear theory based on the Boltzmann–Volterra heredity theory. The model is written in the form of the functional of full potential deformation energy. The calculation algorithm is based on the Ritz method and iteration method. Calculation results for several options of shallow shells of double curvature, square of base, made of plexiglass, are presented. Contour fixation—fixed pin joints; uniformly distributed load is directed along the normal to the surface. “Deflection–time” relations are plotted for different load magnitudes. Values of critical time of buckling as a result of creep deformation are found. Curves of critical load decline over time as a result of creep development are obtained.