Study On Stability Bearing Capacity Of 6082-T6 Aluminum Alloy Tube Under High Temperature

As a new type of material,aluminum alloy material has been widely used in sports center,stadium,exhibition center,large-scale transport station and terminals,industrial plants and other infrastructures.China's economy has maintained high-speed and stable growth,infrastructure construction has been vigorously developed,and the demand for large-scale public buildings in various regions is growing,which is a huge opportunity and challenge for the high-tech field of China's construction industry.Aluminum alloy material has become one of the first choice of many building materials because of its light weight and high strength.However,due to its low melting point,the properties of aluminum alloy materials at high temperature greatly reduce or even lose the bearing capacity.At present,there is little research on the high temperature mechanical properties of domestic 6082-T6 series aluminum alloy.At the same time,China's code for design of aluminum alloy structures(GB50429-2007)lacks relevant provisions for the calculation of bearing capacity of aluminum alloy structures at high temperature.Therefore,the research on the material properties and mechanical properties of the domestic 6082-T6 series aluminum alloy at high temperature has become an important research topic in the field of aluminum alloy structure.In order to further study the deformation performance,failure mode and bearing capacity of aluminum alloy components at high temperature,the following research work is carried out in this paper:Firstly,the high temperature tensile test of 6082-T6 series of domestic aluminum alloy was carried out,and the material properties of aluminum alloy at high temperature were obtained.In this paper,the compression bending tests of 6082-T6 series aluminum alloy tubes under different eccentric conditions were carried out at room temperature,100~oC,200~oC and 300~oC,respectively.The load-displacement curves,change trend of stable bearing capacity,deformation characteristics and failure mode of the members were obtained.Test phenomena and test data show that:the failure mode of compression bending members under different temperature conditions is the overall instability failure;at 100~oC,the bearing capacity performance is more than 10%lower than that at normal temperature;when the temperature rises to 300~oC,the ultimate bearing capacity of members drops more than than 67%.Secondly,the large-scale finite element software ABAQUS is used to simulate the bending test of 6082-T6 aluminum alloy members.The refined finite element analysis model under various working conditions is established through the equivalent simplification treatment of the member bending test.By comparing the numerical simulation results with the test results,the validity and accuracy of the refined finite element analysis model are verified,and the load midspan deflection curve and the change trend of ultimate bearing capacity of aluminum alloy members under different temperatures are obtained.Finally,through the comparative analysis of the test data and numerical analysis,it is verified that the calculation method of the stable bearing capacity of the medium pressure bending members in the code for design of aluminum alloy structures(GB50429-2007)at room temperature is suitable for the calculation of the bearing capacity of the 6082-T6 aluminum alloy tube compression bending members made in China in this test.On this basis,according to the calculation method of stable bearing capacity of aluminum alloy bending members in Eurocode 9,the recommended value of reduction coefficient of domestic 6082-T6 aluminum alloy tube at different temperatures is fitted,and the calculation formula of high temperature bearing capacity of 6082-T6 aluminum alloy tube bending members is given.