Research On The Expansion Tube Energy Absorber’s Energy Absorption Characteristics And Application

Expansion tube energy absorbers are used in the designs of energy absorber widely.The expansion tube energy absorbers have the advantages of long energy absorption stroke and stable buffering force,and also possess the advantage of being insensitive to impact load directionality meanwhile.Expansion tube energy absorber is an ideal energy absorber.In order to make full use of the expansion tube energy absorber,its energy absorption characteristics should be further studied.Therefore,the quasi-static compression test,dynamic impact test,theoretical model establishment and numerical simulation of the expansion tube energy absorber structure are performed in this paper.According to the research results,an expansion tube energy absorber needed for the engineering was designed and verified by experiments.This article provides a certain theoretical and experimental basis for the application of the expansion tube energy absorber structure.Firstly,the mechanical properties of expansion tube materials are studied by using the Instron standard electronic universal material testing machine in this article.Then,an electro-hydraulic servo multi-channel loading tester was applied to perform the first set of quasi-static compression tests on the expansion tube energy absorber assemblies.The parameterized expansion tube energy absorption characteristics under quasi-static compression are obtained.Then,a high-speed dynamic impact test was performed on the expansion tube energy absorber using a drop weight impact tester to verify the rationality of the structure and the dynamic impact response characteristics of the expanded tubular energy absorber under high-speed impact conditions.The parameter-based dynamic shock response characteristics of the expansion tube and the influence of different impact velocity on the characteristic energy absorption characteristics of the expansion tube energy absorber are obtained.Secondly,a new deformation mechanism of the expansion tube is adopted in this paper.The deformation mode adopted is composed of straight lines and arc segments.The slope of the curve of the deformation mechanism profile is continuous.In addition to the deformation mechanism used,the effects of strain hardening and friction are also added.Finally,this paper use ANSYS/LS-DYNA software to carry out numerical simulation of multiple groups of dynamic impact tests.At the same time,multiple sets of test results are used to modify and change the numerical simulation settings.Based on the theoretical model and the reliability of numerical simulation,the research of the expansion tube energy absorber is directed.And through the theoretical derivation and simulation conclusions,a structure of expansion tube absorber designed for practical engineering is designed,and the designed structure is tested and verified.