Application of nonlinear link in strut and tie model for joint planar expansion

Abstract

An application of nonlinear link with strut and tie model of seismic retrofit technique for existing reinforced concrete beam-column connections using planar joint expansion is proposed. The model is constructed based on experimental results of one control specimen, three retrofitted specimens and FEM analysis of strengthening method proposed by authors. Truss model which represents behavior and flowing of force in joint and planar expansion is constructed based on strut and tie concept. Nonlinear link is added in critical elements to represent nonlinear behavior. By solving statically indeterminate truss and checking strut and tie limitation, the design region solution is received. The model is not only predicts close value of maximum column shear force, failure mode and joint shear force but also predict column capacity and displacement relation. Proposed simplify strut and tie model is helpful for practical engineer in designing planar joint expansion retrofitting beam-column connection.