The Effect of a Moving Strip Load on a Discretely Reinforced Cylindrical Shell

The study solves the problem of quasi-static deformation and stability of a cylindrical shell discretely reinforced with a cyclically symmetric system of stringers along which moves a uniformly distributed radial load. Due to the cyclic symmetry of the problem, a shallow panel with one stringer is conceptually isolated from the shell and further solutions are performed for that individual panel. The meridional edges of this panel may have boundary conditions of either symmetry or antisymmetry, depending on the expected buckling mode of the entire shell. The reinforcing effect of the stringer (considered as a beam) is incorporated in a contact formulation. The problem is solved in a contact formulation and in a quasi-static version. The problem is reduced to a system of two differential equations with discontinuous coefficients, which is associated with the discreteness of stringer position. In addition, the equations include load movement velocity as a parameter. The equations are solved by the Bubnov method. The resulting system of linear algebraic equations is solved in the regular way. Two special cases of the problem formulation, characterized by different ways of considering shell and stringer stiffness, are considered. In the examples given, the influence of stringer stiffness on the critical velocity of load movement is analyzed in various formulations.