Finite element modeling of energy absorption characteristic of hybrid structure - composite wrapped on a square metal tube

Abstract

The study of axial crush behavior of metal and composite tube has become a basis for the design of crashworthy structure in automotive and aircraft applications. Unlike metals, polymer composite material displays little or no plastic deformation characteristics. Research has showed that the hybrid tube usually made of inner aluminum tube over-wrapped with Eglass fiber reinforced epoxy have significantly higher energy absorption than either aluminum tube or composite tube. It is therefore important to have a predictive design tool that could simulate the response of the hybrid structure under impact or crush load. This thesis is aimed at the development and validation of finite element simulation methods for hybrid tubes. The axial crushing behavior and the energy absorption capacity of the aluminum-composite hybrid tube under quasi static and impact loading is studied using the LS-Dyna finite element solver. A square aluminum tube externally wrapped with E glass/epoxy composite layer at ±45° to tube axis is used for finite element analysis. A modified Chang-Chang failure model is used for the composite layers, exhibiting reasonable correlation with the experimental results. Simulations are carried out on composite and aluminum tubes separately. The results indicate that the energy absorption and crush behavior of the hybrid tubes are better than either the composite tubes or the aluminum tubes. In addition, analysis are also conducted on finite element tube to determine the effects of adhesion, ply orientation, and trigger geometry on load displacement response of hybrid tube.