| Aluminum alloy materials have been widely used in spatial structures and bridge structures in recent years due to their advantages of corrosion resistance,light weight,high strength,environmental protection and non-magnetic.In the study of aluminum alloy,the stability of the component is more critical.When it comes to structural design in civil engineering,axial compression members are one of the most basic structural types.In recent years,6082-T6 aluminum alloy,as a new type of aluminum alloy in the 6XXX series,is superior to the traditional 6061-T6 aluminum alloy in terms of strength,corrosion resistance and welding performance,so it has a wide application prospect in the field of civil engineering.In order to further study this new material,this paper carried out systematic numerical simulation and theoretical research to evaluate the reliability of 6082-T6 aluminum alloy axial compression members.The specific research contents and results are as follows:(1)The finite element analysis is carried out,and the relevant parameters required for the finite element analysis are set up,including element selection,meshing and boundary conditions.The existing tests are simulated,and the comparative analysis is carried out from the perspective of the shape and force state of the specimen.The results show that the correctness of the finite element modeling method and the validity of the finite element model are verified from the perspective of shape and force state,which can provide a reliable finite element modeling method for the subsequent analysis of aluminum alloy axial compression members.In this paper,three classical constitutive models and measured stress-strain curves of domestic 6082-T6 aluminum alloy were studied,and the influence of different calculation methods in Ramberg-Osgood constitutive model on hardening index n was compared.Through comparative analysis,it is found that the stress-strain curve of 6082-T6 aluminum alloy is consistent with the Ramberg-Osgood constitutive model,and the calculation method of hardening index proposed by Steinhardt can be well applied to this material.(2)The specimens were divided into short,medium and long specimens by calculating the relative slenderness ratio.Based on the reliable finite element modeling method,the specimens were numerically simulated.The simulation results show that the local buckling occurs in the small length specimen(λ≤0.5),the coupling failure of local buckling and overall buckling occurs in the medium length specimen(0.5<λ<2.0),and the overall instability failure occurs in the long specimen(λ≥2.0).The various factors affecting the stability of aluminum alloy axial compression members are studied,including initial bending,material parameters and section size.The analysis results show that the stability coefficient of the aluminum alloy axial compression column will be affected by the initial bending,material parameters and section size,and the initial bending has a great influence on the stability coefficient.When the slenderness ratio is different,these factors have different effects on the stability coefficient of the component.(3)According to the finite element simulation results and parametric analysis values of this paper,a refined calculation formula based on the stability coefficient in the design code of aluminum alloy structures in China is proposed.A set of stability coefficient calculation formulas are proposed for columns with different slenderness ratios.The proposed formula is used to calculate the axial compression stability coefficient,and it is compared with the calculation method in the current code.The comparison shows that the proposed calculation formula obtained in this paper is the closest to the finite element simulation results,showing higher accuracy and reliability. |
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