Creep Age Forming Simulation And Springback Study Of 7075 Aluminum Alloy FSW Component Based On ABAQUS

With the rapid development of aviation industry,the traditional riveted aircraft structure has been replaced by large integral panels,thus the creep aging forming technology emerged.The stiffened panels are widely used in the wing and fuselage of aircraft.At present,the stiffened panels of large-scale integral panels are machined by milling.However,this method not only has low material utilization and long processing cycle.Aging forming technology of integral welded panel oriented to high efficiency welding technology can be widely used in aircraft manufacturing,so the integrated rib structure based on Friction Stir Welding-Aging Forming is an important development direction to reduce aircraft manufacturing costs,and also has important application value to improve the forming performance of the integral rib structure.In this paper,the creep uniaxial tension of typical aviation 7075-T651 aluminium alloy is carried out on CSS-3905 creep tensile test machine at constant temperature(180 ?)and constant stress(130 MPa and 160 MPa).The parameters of creep constitutive model of Time-Hardening are calculated by creep tensile data.Error analysis of creep constitutive fitting data and test data verifies the accuracy of Time-Hardening constitutive model.The results show that the constitutive model can describe the creep behavior of 7075 aluminum at 180?.The T-type structure in the integral ribbed plate structure is selected as the research object.Baseing on the bending forming theory,the mechanical characteristics and qualitative springback analysis of T-type structure are carried out.Basing on ABAQUS finite simulation analysis software,the wall plate and rib are connected by ABAQUS self-contained Tie(binding)constraint.The finite element simulation model of creep aging forming of T-type FSW structure is established.Through theoretical analysis,the finite element model of creep aging forming of T-type FSW structure is established.The applicability and accuracy of the finite element simulation model for creep aging forming of T-type FSW members are proved by means of test verification.Then the creep aging forming process of T-type FSW members are simulated and tested.Basing on the simulation results,the stress,creep and springback during creep aging forming of T-type FSW members are analyzed.The effects of different aging parameters(die radius,time and loading pressure)and geometric dimensions of T-type structure(wall thickness,stiffener thickness ratio)on springback of T-type FSW structure are also analyzed.The creep aging deformation law of T-type FSW structure under the above parameters is obtained.Basing on the displacement compensation correction method of geometric node of die surface,the springback compensation principle of creep aging forming of T-type structure is proposed.Basing on ABAQUS finite element analysis platform,the finite element simulation model of creep aging forming of T-type FSW structure is established.The springback simulation analysis of creep aging forming of T-type FSW structure is realized,and the virtual modification iteration of the shape of T-type FSW structure in this process is completed.The die surface of T-type FSW structure during creep aging forming is changed,and the feasibility of the springback compensation principle for creep aging forming of T-type structure is verified.