MULTIPLE BARRELLING IN AXIAL COMPRESSION OF CYLINDRICAL TUBES

Abstract

QUASI-STATIC AXIAL COMPRESSION TESTS WERE CONDUCTED ON ALUMINIUM ROUND TUBES OF DIF FERENT DIAMETER TO THICKNESS (D/H) RATIOS. ALL THE TESTED TUBES DEFORMED IN AXISYMMETRIC MODE. HOWEVER THOSE HAVING D/H RATIO LESS THAN AROUND 8 COLLAPSED IN MULTIPLE BARRELLING WHILE OTHERS IN CONCERTINA MODE. THE PRESENT PAPER SPECI¯CALLY DEALS WITH THE DEVELOPMENT OF, AXISYMMETRIC MULTIPLE BARRELLING MODE OF COLLAPSE WHILE CONCERTINA MODE OF COLLAPSE IS PRESENTED IN OUR PREVIOUS PAPER [4]. THE COMPRESSION PROCESS WAS ALSO NUMERICALLY MODELLED USING NON-LINEAR FINITE ELEMENT CODE FORGE2 [3]. THE TUBE MATERIAL WAS MODELED AS RIGID-VISCOPLASTIC. A COMPUTATIONAL MODEL OF COMPRESSION PROCESS IS PRESENTED. EXPERIMENTAL AND COMPUTED LOAD-COMPRESSION AND ENERGY-COMPRESSION CURVES AND DEFORMED SHAPES OF THE TUBES ARE COMPARED. PREDICTED VARIATIONS OF EQUIVALENT STRAIN, EQUIVALENT STRESS AND DIFFERENT COMPONENTS OF STRAIN RATE AND STRESS TENSORS ARE PRESENTED AND DISCUSSED. EFFECT OF FRICTION PRESENT BETWEEN TUBE-PLATEN INTERFACES ON THE DEVELOPMENT OF MODE OF COLLAPSE IS ALSO PRESENTED AND DISCUSSED. ON THE BASIS OF THE EXPERIMENTAL AND COMPUTATIONAL FINDINGS MECHANICS OF MULTIPLE BARRELLING IS DISCUSSED.