LAUSR

BUCKLING MODE INTERACTION IN COLD-FORMED STEEL (CFS) MEMBERS MUST BE CONSIDERED FOR THE STRUCTURAL DESIGN, SINCE THE MODAL INTERACTION MAY LEAD TO A SIGNIFICANT REDUCTION OF THE STRUCTURAL STRENGTH, USUALLY RECOGNIZED AS EROSION OF THE LIMIT LOAD. SO FAR, THE DISTORTIONAL-GLOBAL (DG) BUCKLING INTERACTION IS NOT COVERED BY CODES, E.G. BRAZILIAN CODE NBR 14762 (2010). THE PRESENT INVESTIGATION IS AIMED AT THE DG INTERACTION OF CFS LIPPED CHANNEL (LC) COLUMNS, WHICH IS THE MOST USUAL SECTION IN MANY APPLICATIONS. THE METHODOLOGY EVOLVES A PARAMETRIC ANALYSIS, OVER A SINGLE LC COLUMN UNDER DG BUCKLING INTERACTION. FIRST, A STUDY OF INITIAL GEOMETRIC IMPERFECTION (IGI) SENSIBILITY IS PERFORMED, WITH THE PURPOSE OF UNDERSTANDING THE INFLUENCE OF THE IGI ON THE COLUMN’S BEHAVIOR. MOREOVER, THE PARAMETRIC ANALYSIS IS EXTENDED TO A SET OF YIELDING STRESS AND COLUMN LENGTHS, IN ORDER TO UNDERSTAND THE ULTIMATE LOAD UNDER DIFFERENT TYPES OF DG BUCKLING INTERACTION NATURES. CONCLUSIONS ON THIS RESEARCH HAVE BEEN SHOWN THAT THE ACTUAL GLOBAL BUCKLING EQUATION FROM THE DIRECT STRENGTH METHOD (DSM) IS ALREADY SUITABLE TO COVER THE DG BUCKLING INTERACTION FOR THE CASE OF LIPPED CHANNEL MEMBERS UNDER AXIAL COMPRESSION.