高强铝合金板件螺栓连接高温抗剪性能研究OA

High-temperature material tests were conducted on 7075 high-strength aluminum alloy to investigate the stress-strain curves and the variation of key mechanical parameters with temperature.High-temperature shear bearing tests were then carried out on 7075 high-strength aluminum alloy plate bolted connections at high temperatures,to examine the influence of temperature and edge distance on the failure modes and ultimate bearing capacity of specimens.The test results show that when the temperature is above 200℃,the elastic modulus and strength of the material begin to decrease significantly.When the temperature reaches 300℃,the yield strength and ultimate strength of the material are both about 15%of those at room temperature.The shear connection specimens exhibit two failure modes,namely net cross-section failure and mixed failure,and both temperature and edge distance can affect the failure mode of the specimen.The degradation of the ultimate bearing capacity of specimens shows a trend similar to the reduction in material strength at high temperatures.When the temperature reaches 300℃,the ultimate bearing capacity of specimens decreases to about 15%of that at room temperature.The ultimate bearing capacity of the specimen increases with the increase of edge distance.When the edge distance increases from 1.0d0 to 1.5d0,the ultimate bearing capacity approximately doubles.When the edge distance increases from 1.5d0 to 2.0d0,the increase in ultimate bearing capacity is limited.The established finite element model can accurately simulate the shear performance of bolted connections and shows a certain degree of reliability.The experimental results were compared with the calculation results of domestic and foreign codes,and the results showed that the calculation results based on various national codes were relatively conservative when the edge distance was not less than 1.5d0.