The FE Numerical Simulation Research On The Bending Springback Of Cap-type Profile

Aluminum alloy Cap-Type profile is widely used in the areas of automotive andaerospace, and NC rotary-draw bending is one of the main forming methods of Cap-Type profile. But because of the complexity of rotary-draw and the thin wall, semi-hollow of Cap-Type profile, the wall thickness, wrinkling and springback are easilyproduce during the rotary-draw bending process, especially the springback whichaffects the quality of bending parts seriously. Therefore, the rotary-draw bending andunloading springback process of Cap-Type profile were analyzed by using finiteelement numerical simulation mostly combined with experimental and theoreticalmethods, and influence laws of forming parameters on springback were studiedsystematically. The achievements of this research have important guiding significanceand reference value on the application and popularization of rotary-draw bendingtechnology of aluminum alloy Cap-Type profile and design and optimization of processparametersontheformingprocess.Abriefintroductionofthispaperanditsmainresultsare as follows：First，the basic mechanical property parameters of5052aluminum alloy Cap-Typeprofile are obtained through the experiment, and then the constitutive model isestablished. A3D-FE model of rotary draw bending process and the unloadingspringback of5052aluminum alloy Cap-Type profile are established based onABAQUS platform combined with forming characteristics after solving some keytechnology problems of forming process, during the establishing process, actualsituation and both computation accuracy and efficiencywere taken into account, and itsreliability is validated by experimental and theoretical methods.Then, based on the FE model, the distribution situation of S.Mises and logarithmicstrain and the characteristic of springback are detailed descripted during the springbackprocess. The results indicate that: the springback mainly appliance at bending segment,and the rate is stably, the stress changs most in the springback from start to finish, inparticular, stresses in the tangential and radial direction have more obvious release.At last, the influence laws of forming parameters of Cap-Type profile in rotary-drawbending process are obtained by using the model established above. The results showthat: the springback angular and springback radius increase with the increase of the bending anger, relative bend radius, bent speed, boost speed, the clearances amongclamp, bend die and profile, the friction coefficient between pressure die, materialstrength coefficient and initial yielding stress; while decreases with the increase of theclearance between pressuredie and profile and the friction coefficient amongclampdie,bend die and profile and the Young’s modulus, hardening index. But the influences ofthe clearance and friction between wipe die and profile on springback are notsignificantly.