Study On Bearing Capacity Of 7A04-T6 Aluminum Alloy Rectangular Tube Simply Sup-Ported Beam

Aluminum alloy has good properties,such as high specific strength,easy manufacture,easy processability,large ductility,excellent thermal conductivity,high corrosion resistance and beautiful appearance.It has broad application prospects in construction engineering.At present,5000 and 6000 series aluminum alloys are mainly used in aluminum alloy building structures,but the strength of 5000 and 6000 series aluminum alloys is difficult to meet the needs of high-rise buildings or long-span structures.Compared with 6000 series aluminum alloy,7A04-T6 aluminum alloy specimen has higher specified non proportional extension strength and ultimate tensile strength,reaching the strength of high-strength steel.However,the research on the bearing capacity of 7A04-T6 aluminum alloy flexural members is still very limited.Therefore,the research on the bearing capacity of 7A04-T6 high strength aluminum alloy rectangular tube flexural members is carried out in this paper.The main work is as follows:(1)The uniaxial tensile tests of 14 7A04-T6 aluminum alloy specimens were carried out,and the mechanical properties parameters of 7A04-T6 aluminum alloy were obtained.The stress-strain curves were compared with Ramberg Osgood,and the constitutive model of 7A04-T6 aluminum alloy was established.(2)14 three-point bending specimens and 18 four point bending specimens are studied.There are two section forms and 17 slenderness ratios in the specimens,and the load displacement curves of the specimens are obtained.The test results show that all specimens have overall instability and a few specimens have fracture failure.(3)The corresponding finite element model is established,and the effectiveness of the model is verified by comparing with the experimental results.Then,the effects of initial defects,width-thickness ratio,height-width ratio and span of aluminum alloy rectangular section beam on the bending capacity of aluminum alloy rectangular section beam are analyzed by expanding parameters.The results show that these four factors have different effects on the stability of members: the initial defect value has little effect on the bending bearing capacity of specimens,while the section height width ratio and width thickness ratio have a great effect on the bearing capacity of specimens,the span has a great effect on the bearing capacity of specimens with large slenderness ratio,and has little effect on the bearing capacity of specimens with small slenderness ratio.(4)The test values and finite element calculation results of the flexural member bearing capacity of 7A04-T6 aluminum alloy rectangular pipe are compared with the calculation results of three current aluminum alloy design codes and two calculation methods,and the calculation formula of the flexural member bearing capacity of 7A04-T6 aluminum alloy rectangular pipe adjusted based on the European aluminum alloy structural design code is proposed.