Modeling the steel-jacket strengthening of a reinforced concrete pipe rack column, accounting for material nonlinearity
Abstract
Modeling the steel-jacket strengthening of a reinforced concrete pipe rack column, accounting for material nonlinearity
Incoming article date: 19.12.2025The paper presents a finite element model of a reinforced concrete viaduct column retrofitted with a steel jacket. The model was developed in ANSYS software, accounting for material nonlinearity and contact interactions between the concrete column and the steel jacket. The selection of finite element types, material constitutive laws, and the friction coefficient is justified. Numerical simulations revealed three distinct stages in the composite behavior of the column–jacket system under loading. Particular attention was given to the analysis of the contact interface and the investigation of the steel–concrete friction coefficient, which significantly influences the system response at each loading stage and serves as the basis for distinguishing these stages. The study demonstrates that accounting for the composite action between the reinforced concrete column and the steel jacket yields an additional load-carrying capacity reserve of up to 16% compared to separate, non-composite design calculations. Furthermore, the paper includes an analysis of the influence of the spacing of transverse tie plates of the jacket on the load-carrying capacity of the retrofitted column and identifies optimal ranges for this spacing.
Keywords: material nonlinearity, stress–strain relationship или Constitutive law, steel jacket, Pipe rack column, coefficient of friction, strengthening, finite element model, reinforced concrete, composite action, nonlinear stress–strain model