Impact Energy Absorption of Concentric Circular Tubes

Abstract:- Non-linear finite element code ABAQUS/Explicit was employed to evaluate the energy absorption characteristics of concentric circular tubes subjected to impact in the axial direction. Thin-walled circular tube plays a vital role as energy absorber due to its high energy absorption capacity. However, the main drawback of existing tube type energy absorber is the high initial peak load. This work evaluates the capability of concentric circular tubes in reducing the peak load that is exerted to the protected structures and occupants during impact. Clearance and thickness of the structure were varied and different materials such as aluminum alloy, high strength steel and stainless steel were used. The study found that aluminum alloy has great potential to be utilized as energy absorbing system due to its high specific energy absorption capacity and long stroke. For all materials, increasing the clearance between the inner and outer circular tubes resulted in a reduction of peak load and a significant increase of specific energy absorption (SEA). However, increasing the thickness adversely increased the initial peak load and reduced the SEA. It can be deduced that concentric circular tubes could be utilized as a safer design of energy absorber as it exhibited a lower initial peak load during impact which is a desirable feature when designing for occupant safety. Key-Words:- structural crashworthiness, impact energy absorption, non-linear explicit finite elemen