INVESTIGATION OF THE ENERGY ABSORPTION CHARACTERISTICS OF METALLIC TUBES WITH CURVY STIFFENERS UNDER DYNAMIC AXIAL CRUSHING

Abstract

THIN WALLED MULTI-CELL COLUMNS ARE HIGHLY EFFICIENT ENERGY ABSORBERS UNDER AXIAL COMPRESSIONS. MULTI-CELL FEATURES ARE USUALLY OBTAINED BY PLACING STIFFENERS OR RIBS TO GET THE REQUIRED GEOMETRY FEATURES IN THE COLUMNS. IN THIS STUDY, THE CURVED STIFFENERS WITH VARYING NUMBERS IN DIFFERENT CONFIGURATIONS ARE USED TO SUPPORT THE CIRCULAR SINGLE AND BI-TUBULAR METALLIC TUBES AND THEIR SHAPE, POSITION AND NUMBER EFFECTS ARE NUMERICALLY INVESTIGATED UNDER DYNAMIC AXIAL CRUSHING LOADS. NUMBER OF CONFIGURATIONS CAN BE CLASSIFIED BY THE NUMBER OF TUBE/TUBES AND CURVED STIFFENED SHELLS. THIS STUDY CAN BE DIVIDED IN THREE PARTS; SINGLE TUBES WITH CROSS-CURVED STIFFENERS WITH EQUAL NUMBER OF CELLS, SINGLE TUBES WITH CURVED STIFFENED WALL SUPPORTS WITH ASCENDING NUMBER OF STIFFENERS, AND BI-TUBULAR TUBES WITH ASCENDING CROSS-CURVED STIFFENERS. THE MASS IN EACH CONFIGURA-TION IS MAINTAINED AS SAME BY ADJUSTING THE THICKNESSES OF THE STIF-FENERS. ENERGY ABSORPTION FOR ALL OF THE CONFIGURATIONS ARE COMPARED WITH PUBLISHED EXPERIMENTAL LITERATURE OF STANDARD SINGLE TUBE AND BI-TUBULAR TUBE WITH CROSS-STRAIGHT STIFFENERS. DEFORMATION MODES AND ENERGY ABSORPTION CHARACTERISTICS ARE EVALUATED AND DISCUSSED FOR ALL OF THE PROPOSED CONFIGURATIONS. RESULTS INDICATE THAT THE PROPOSED CONFIGURATIONS WITH CURVY STIFFENERS ARE SUPERIOR IN ENERGY ABSORPTION WITH INCREASED MEAN CRUSHING FORCE AND ENHAN-CED SPECIFIC ENERGY ABSORPTION ALONG WITH A HIGH VALUE OF CRUSH FORCE EFFICIENCY IN COMPARISON WITH THE REFERNCE CONFIGURATIONS. BI-TUBULAR CONFIGURATIONS WITH CURVY STIFFENERS SHOW A MORE STABALIZED RESPONSE WITH THE LOWEST PEAK CRUSHING FORCE IN ALL OF THE PROPOSED CONFIGURATIONS.