Research On Elastic-plastic Buckling And Crashworthiness Of Thin-walled Metal Tub

Thin-walled metal tube as a buffer and energy absorbing unit both radial or axial plastic deformation have very good cushioning effect of energy absorption, and could reduce the impact of the collision reaction force, the tubes will eventually produce a regular deformation mode under impact of the collision.It is widely used in various industries for the design of passive safety protection in impact, but for the design of passive safety protection of retractable roof structure which is a moving structure sometimes, there is no use of precedent. Therefore, the research group made a further study for the use of passive safety protection the feasibility and design theories of the thin-walled metal tube in the retractable roof structure.As we know the research results of plastic deformation of thin-walled metal tube under static and dynamic load of impact in axial and radial are based on empirical formula and experimental results. For the axial and radial crushing strength and the anti- plastic deformation and energy absorption of the theory are not perfect, this paper carried out theoretical research in this area.By the theoretical analysis and finite element method(FEM),the failure modes,mechanical properties and energy absorption capacity for thin-walled metal tubes under axial and radical static compression and dynamic impact are carefully studied in this paper,the facts which affect these failure modes and energy absorption capacity are summarized in the paper ,including the geometrical size of the tubes ,impact velocity and impact mass,and also considering the effect of strain rate and strengthen.And then derived reaction force of collision theory formula under two different types of compression load. Followed by LS-DYNA finite element software ,the contents of the simulation analysis, consistent with the results of the theoretical formula, which verifies the correctness of the theoretical formula.This theory research has great significance for the future use of thin-walled metal tube in design of passive safety protection.