Study On Mechanical Properties Of Aluminum Alloy Gusset Joint Under Cyclic Loading

The mechanical properties of aluminum alloy are similar to those of steel.Its density is only 1/3 of that of steel.It has the advantages of corrosion-resistant environment,beautiful appearance and light weight.At the same time,lighter weight can alleviate the burden on the support end.More reflected in the building structure.The aluminum alloy space grid structure has been widely used in the field of large-span building structures in China,and the plate-type node is one of its main node forms.The aluminum alloy space reticulated shell has a light weight,and under the action of large wind loads,there is a danger of node damage and roof collapse,which causes serious direct and indirect economic losses.Compared with a large number of static performance studies,the current experimental research on the dynamic performance of the plate joints is still scarce,and there is no research result of the plate joints and double-layer joints of the aluminum alloy Hook bolts.Therefore,the power of the plate joints is Performance test and numerical simulation research have obtained some research results with guiding significance and application value.Based on the dome structure of the coal storage bin of Caofeidian Coal Storage Base of Kailuan Group,the experimental full-scale joints were used to carry out experimental research.The weak parts,failure mode and energy dissipation capacity of single-layer plate joints and double-layer plate joints under reciprocating load are discussed.The full-scale test of five aluminum alloy plate joints under reciprocating load across mid-plane plane is completed.The refined nonlinear finite element numerical analysis was carried out,and the experimental simulation results were basically the same.Based on the experimental data and the results of finite element analysis,it is found that the energy consumption of the nodes is general.The bearing capacity of the double-layer Hooke bolt connection node is 1.94 times that of the singlelayer node and 2.5 times that of the single-layer node.The form of damage under bolted connections is different.Based on the background of low-cycle fatigue failure of aluminum alloy space grid structure subjected to repeated loads under strong wind,10 low-cycle fatigue performance tests of bolt-plate joints were carried out,which provided a theoretical basis for the analysis of fatigue performance of the whole joint.A full-scale test of 6 nodes was carried out to explore the fatigue life of aluminum alloy plate joints.Combined with the failure mode,energy dissipation capacity and fatigue life of aluminum alloy plate joints,the design theory and method under dynamic load are enriched.The research shows that when the node is broken,the strain level on the connecting plate and the H-shaped bar is low,the load displacement curve is not full,and a large amount of heat is generated between the beam and the disk,causing the node temperature to rise.At the same time,the S-N curve and the modified Neuber method are used to simulate the fatigue life of the joint.The calculated life value and the measured results are in good agreement.The error between the local concentrated stress simulation value and the actual calculated value can be controlled at 10%.