The Study Of Compression Instability Load Estimated Methods Of New Stiffened-welded Aircraft Plate

With reinforced wall welding can reduce the overall weight, as the welding technology becomes more and more mature, therefore, in aircraft wings and fuselage structure is widely used. However, as continuous emergence of new welding siding and changing of the size, lead to the test costs continue to increase, so study the method from engineering calculations and Simulation Finite Element Analysis estimated structural instability load is necessary. Study a large Z-shaped reinforced welded panels in the paper, analyzed with engineering theory and Abaqus finite element simulation, compared with the experiment, research the methods of instability pressure under the axis load.Firstly according to planar buckling formula studied local buckling load, secondly, using Johnson-Euler method to calculate the instability limit load. As calculated the effective width and sectional radius of gyration was complex, drew graph showed the relationship, in order to improve the efficiency. After built that the skin and stringers have different materials how to get the average load, compared with the experimental data, the error limit load is 4.36%.Finite element simulation combined the Buckle linear eigenvalues buckling with Static, risks arc, analyzed the process of instability, as we know that skin first buckling then the stringers, finally overall instability; by getting extreme value of the load scale factor determined limit load. There were three modeling for comparison, so as the shell-shell, shell-entity and entity-entity, compared with the experimental data, after analyzed mesh size and open welding of skin-stringers contact position influence the instability load. Finally shell-solid limit load resulting modeling better error is 4.1%.Then application of this finite element modeling method analyzed the impact of skin, stringers elastic modulus and boundary conditions of the limit load of the panel, results that the elastic modulus of the stringers can improve the overall limit load easily; at the same time result show that the linear displacement can be better increase the value than angular displacement, aside constraints also has a significant impact on improving buckling load.The engineering calculations and finite element simulation study can be better estimate the wall instability, providing a reference for subsequent tests, savings and improve efficiency. This analysis can help stiffened welded panels used in aircraft structures.