PARAMETRICAL ANALYSIS OF EXTENDED ENDPLATE SEMI-RIGID JOINTS SUBJECTED TO BENDING MOMENT AND AXIAL FORCE

Abstract

STEEL BEAM-TO-COLUMN JOINTS ARE OFTEN SUBJECTED TO A COMBINATION OF BENDING AND AXIAL FORCES. THE LEVEL OF AXIAL FORCES IN THE JOINT MAY BE SIGNIFICANT SUCH AS IN PITCHED-ROOF PORTAL FRAMES, SWAY FRAMES OR FRAMES WITH INCOMPLETE FLOORS. CURRENT SPECIFICATIONS THAT TAKE IN ACCOUNT THE STEEL SEMI-RIGID JOINT BEHAVIOUR DO NOT CONSIDER THE SIMULTANEOUS PRESENCE OF AXIAL FORCES (TENSION AND/OR COMPRESSION) ACTING IN THE JOINTS. ON THE OTHER HAND, AN EMPIRICAL LIMITATION OF 5% OF THE BEAM PLASTIC RESISTANCE IS THE ONLY LIMITATION SUGGESTED IN THE EUROCODE 3. IN THE CASES WHERE THE AXIAL FORCE MAGNITUDE ACTING IN THE JOINT IS LESS THAN THIS LIMIT, ITS EFFECTS CAN BE DISREGARDED IN THE JOINT DESIGN. DESPITE THIS FACT, THE COMPONENT METHOD, PROPOSED IN THE EUROCODE 3, CONTEMPLATE THIS SITUATION SINCE ANY COMPONENT CAN BE CHARACTERIZED, FOR ANY LOAD TYPE ACTING ON THE JOINT. THIS WORK PRESENTS A PARAMETRICAL ANALYSIS OF BEAM-TO-COLUMN JOINTS SUBJECTED TO BENDING MOMENT AND AXIAL FORCE WITH THE AID OF A MECHANICAL MODEL BASED ON THE EUROCODE 3 RECOMMENDATIONS. THE PARAMETRIC ANALYSIS CONSIDERS SEVERAL FACTORS THAT IN°UENCE THE JOINT GLOBAL BEHAVIOUR SUCH AS PLATE THICKNESS, BEAM HEIGHT, COLUMNS SECTIONS AND THE NEUTRAL AXIS POSITION.