Time-dependent Yield Moment Model for Deteriorated Steel Connections

摘要

Steel structural connections are integral parts in steel structures. They are widely used in building frames to join different structural members together as well as to support gravitational load, shear load and bending moment and to transmit them to the adjacent structural components. However, gradual thinning of steel due to corrosion damage reduces their load bearing capacity, loses structural connectivity and subsequently jeopardises the structural integrity of the entire structure. This paper presents a remaining capacity assessment method, namely time-dependent yield moment model, for steel structural connection derived analytically based on a time-dependent corrosion rate model and yield-line theory. Time dependent yield moment model of steel structural connection is derived analytically as a function of time and geometric parameters of the plate. Solution to a wide-flange-section-to-column-baseplate connection subjected to minor axis bending moment and flush endplate beam-column connection subjected to in-plane bending moment is presented. Results of the analytical expression are compared to a three-dimensional nonlinear finite element model and good agreement is obtained. The proposed model may contribute to the prediction of remaining strength and repair schedule of corroded steel structural connections.