The design of structural steel frames under consideration of the nonlinear behaviour of joints

Abstract

Abstract This paper introduces a method to determine analytically the nonlinear moment-rotation relationship for joints in structural steel frames. This method was developed on the basis of extensive test series performed at the Institute of Steel and Timber Construction, University of Innsbruck, Austria. The most important features of this development were: the joint was divided into the panel zone and the connection; a nonlinear spring model for the panel zone was established and also the connection was simulated by a nonlinear spring. The necessary parameters to define the springs were evaluated from the test series. The field of application includes welded joints as well as bolted joints. The examples at the end of this paper demonstrate how to incorporate practically the influence of nonlinear joint rigidity into the design of unbraced frames.