Failure Modes And Energy Absorption Capacity Of Metallic Tube Under Axial Compression

By the theoretical analysis and finite element method (FEM), the failure modes and energy absorption capacity for metal thin tubes under axial compression and axial impact are carefully studied in this thesis. The facts which affect these failure modes and energy absorption capacity are also presented in this thesis.First of all, a FEM model was carefully examined. The quasi-static buckling and dynamic progressive buckling was observed in the numerical simulations, which were very similar to the experiment results. The failure modes under static axial compression and dynamic impact, the stress-strain history and load-carrying capacity plots are also obtained.Based on a variety of numerical simulations and detail analysis, the facts which affect these failure modes and energy absorption capacity are summarized in the thesis, including the geometrical size of the tubes (length, sectional size, and thickness), axial impact velocity and impact mass. Furthermore, the transfer condition from symmetric failure modes to non-symmetric failure modes and transfer condition from progressive failure modes to Euler buckling failure modes are also presented.The energy absorption capacity of a frusta (conical and inverted conical) were given in the end of this thesis.The facts which can enhance the energy absorption capacity were provided, including the impact section, impact velocity and initial geometrical imperfects.