SECOND-ORDER INELASTIC ANALYSIS OF SHALLOW AND NON-SHALLOW STEEL ARCHES

Abstract

THIS WORK IS BASED ON THE CONTEXT OF THE SECOND-ORDER INELASTIC ANALYSIS (SOIA) OF STEEL STRUCTURES, IN PARTICULAR, STEEL ARCHES. THE ANALYSIS OF ARCHES WITH VARIOUS CHARACTERISTICS, BOTH SHALLOW AND NON-SHALLOW, SEVERAL CROSS SECTIONS AND BOUNDARY AND LOADS CONDITIONS ARE DISCUSSED. FOR THE ARCHES’ SOIA, THE COMPUTATIONAL PLATFORM USED TO SIMULATE THE NUMERICAL MODELS IS THE HOMEMADE CS-ASA, WHICH PERFORMS ADVANCED NONLINEAR STATIC AND DYNAMIC ANALYSIS OF STEEL, REINFORCED CONCRETE AND COMPOSITE STRUCTURES. THE NONLINEAR GEOMETRIC EFFECTS ARE CONSIDERED USING A CO-ROTATIONAL (CR) FINITE ELEMENT FORMULATION; THE MATERIAL INELASTIC BEHAVIOUR IS SIMULATED BY COUPLING THE REFINED PLASTIC HINGE METHOD (RPHM) WITH THE STRAIN COMPATIBILITY METHOD (RPHM/SCM), AND THE STATIC NONLINEAR SOLUTION IS BASED ON AN INCREMENTAL-ITERATIVE STRATEGY (MODIFIED NEWTON-RAPHSON METHOD AND CONTINUATION TECHNIQUES). IN THE SIMULATED NONLINEAR STEEL ARCH MODELS, SPECIAL ATTENTION IS GIVEN TO THE EQUILIBRIUM PATHS, THE INFLUENCE OF RISE-TO-SPAN RATIO, SUPPORT AND LOADING CONDITIONS AND FULL YIELD CURVES AMONG OTHER FACTORS. THE NUMERICAL RESULTS OBTAINED SHOW GOOD AGREEMENT WITH THOSE FROM LITERATURE AND HIGHLIGHT THAT THE ARCH RISE-TO-SPAN RATIO HAS GREAT INFLUENCE ON THE STRUCTURE RESISTANCE AND THAT THE SHALLOW ARCHES CAN LOSE STABILITY THROUGH THE SNAP-THROUGH PHENOMENON.