On Mechanical Properties Of Friction Stir Welded Stiffened Panel Considering The Effect Of Connection

Stiffened panels are capable to reduce the weight of structures by their unique load bearing,improve the production efficiency and economical efficiency. Friction stir welding as a new solid phase joint technology reduces the manufacturing cost and the weight of the structure greatly compared with riveting process. Study on the friction stir spot welding stiffened panels has significant practical value.Strength tests on aluminum alloy friction stir spot welds are conducted, including lap-shear test and cross tension test. The mechanical properties and failure mechanism of the connection area are obtained through the tests.Tension and shearing tests on friction stir welding stiffened panels specimens is conducted to obtain the stability performance, carrying capacity of the structure and the failure load.Riveting stiffened panels’ compression and shearing tests are conducted as comparisons,turned on that the friction stir spot welding process is better than riveting process.Local critical buckling load of friction stir welded stiffened panels under tensile load and shear load is calculated by analyze apply to finite elements software. The experiment results indicate that the failure patterns mainly contain the loosing weld of stiffener and the tearing of skin, and the finite element method is capable to analysis the stability of the structure, which offers a referenced means for the optimization design and engineering application of the structure.Based on the connection strength of the friction stir welds and the mulit-island genetic algorithm in Isight, this paper proposes an optimal design method for friction stir spot welding stiffened panels.The optimal structure of friction stir spot welding stiffness panel under the connection strength constraints is obtained by this method. The optimal structure makes the structure failure load closer to the buckling load and improves the efficiency of the structure. The optimal method is clear and simple,and the light weight comes to good results.