Lateral Behaviors Of Nested Tube Systems Under Quasi-Static Condition

Abstract

A study is made to investigatethe compression behavior of different nested tube systems made of mild steel under lateral compression. The nested tube systems including stacked groups of circular, rectangular and square tubes arebuiltfor application in narrow compressive zones.The deformation mode ofthese systems isobservedand their lateral compression behaviorare identified. The desirable stepwise energy absorption is obtained by designing the nested tube system.The load response revealed that there is no appearance of the peak compressive load in the case of a circular-circular tube (CCT) system, while a circular-rectangular tube (CRT) system offers bigger peak compressive load compared with that of acircular-square tube (CST). The energy absorptions of CCT and CRT systems are smallestand greatest, respectively. This study also estimates the energy absorption capacity of these system. By implementingthe “plastic hinge line” concept of the modified simplified super folding element (MSSFE) theory and superposition principle, the analytical models predicting compressive load of the nested tube systemsare introduced. The analytical investigationsare comparedwith data obtained from tests on these systems. Excellent correlation is observed between the theoretical and experimental data.