Analysis of a steel tubular column filled with equidistant fiber reinforced polymer-ring-stiffening concrete

Based on theory of cylinders subjected to uniform internal pressure, the mechanical performance of a steel tubular column filled with equidistant fiber reinforced polymer (FRP)-ring-stiffening concrete is investigated. The solutions for the stress and displacement are regarded as the superposition of elementary and improved solutions. The elementary solutions are found by using two-dimensional elastic theory. The improved solutions are found by using the Love displacement function method. Considering the conditions of the displacement continuum of the FRP ring and the steel tube exterior, a more accurate solution for an equidistantly FRP-ring-stiffened cylinder subjected to a uniform internal pressure is obtained. Several numerical calculations are also carried out. The results indicate the solutions possess good convergence.