ANALYSIS OF STEEL FRAME INCORPORATING EFFECT OF SEMI-RIGID STEEL CONNECTIONS

Abstract

IS 800:2007 for design of steel structures has provided an opportunity for modern design philosophy as per Limit State Method of design. Steel connections are key elements of steel frame, which affects the behaviour of the steel structures. Shear connections offered little stiffness and rigid connections allow some rotation based on the size parameters of designed connection instead of behaving ideally pinned and rigid connections respectively. Real behaviour of connections is important to understand for safe and economical design of steel structures. In this article to obtain the real behaviour of steel frame with different types of connections, steel frame is analysed considering ideally pinned and rigid end conditions using STAAD Pro. The shear connections are designed for obtained shear force in pinned ended steel frames, while moment connections are designed for shear force and bending moment obtained in rigid ended steel frames. The secant stiffness of the designed connections is obtained using Frye-Morris polynomial mathematical model suggested in IS 800:2007. A steel frame with various connections is presented to demonstrate effectiveness of the method. It has been concluded from the study carried out that economical solutions can be achieved by incorporating the actual behaviour of semi rigid steel connection.