Retrofitting a Column with an Internal Hinge: Analytical and Numerical Study

Abstract

This paper examines the buckling of a column with an internal hinge that is retrofitted with a rotational spring to restore some capacity to carry bending moment at the internal hinge location. The problem is solved analytically to obtain the critical buckling load. In addition a numerical solution is obtained using finite elements with the help of the ABAQUS finite-element analysis software. The results are compared, and design curves are obtained that yield the critical buckling load for the column for various values of the rotational spring stiffness and internal hinge location. The increase in strength of the column with the internal hinge wrapped with one or more layers of reinforcing material is then studied. An analytical expression is found to characterize the reinforcing wrap in terms of the stiffness of an equivalent linear elastic rotational spring. The procedure is validated by a finite-element analysis.