New Insight to Improve Energy Absorption Characteristics of Long Circular Tubes with Stiffeners as Controllable Energy-dissipating Devices

Abstract

Long cylindrical tubes exhibit poor energy absorption due to Euler's buckling mode when they are used as energy-dissipating devices. This paper addresses a new structural design solution with the aim to improve crashworthiness characteristics of long cylindrical aluminium tubes. In this connection, axial stiffeners are introduced into the tube to force the plastic deformation which helps to control the buckling mode. A generic static experimental procedure has been performed in the tubes with stiffeners and the load-displacement curves have been analyzed. The results have been compared with the geometrically identical bare tubes. The results revealed that the tubes with stiffeners would offer energy absorption superior to bare tubes under compressive loading situations. Non-linear finite element analyses have also been carried out to explore the static and axial impact response of stiffened tubes (with axial stiffeners) and bare tubes (without stiffeners) using ABAQUS/Explicit©. The numerically predicted crushing force and fold formation are found to be in good agreement with the experimental results. The results revealed that axial stiffeners can stabilize the deformation behaviour and thus the proposed stiffeners could be a good candidate for enhancing the crashworthiness characteristics of the long cylindrical tubes as a controllable energy absorption element.