Study On Thin-walled Square Tube’s Wrinkling Deformation During Bending Process By Numerical Simulation

Wrinkling is one of the main forming defects of the bending process for thin-walled rectangular tube, which severely restricts the improvement of the formingquality and forming limit. The paper reviews the research on wrinkling deformation ofbending, which are studied using the method such as theory analysis, experimentresearch, numerical simulation based on finite element method, builds the3D-FEquasi-static model for thin-walled rectangular tube bending forming. The wrinklingmechanism and the influencing laws of processing parameters on wrinkling in thebending process are also investigated by numerical simulation method. A briefsummary of the main research contents are as follows:The Q235steel tube’s material performance property is obtained through thetensile test, and the material constitutive equation used for finite element numericalsimulation is established.Considering the influence of press roller, mandrel, hold-down mechanism andcontact boundary conditions, the3D-FE model based on actual production of thin-walled rectangular tube bending forming process is established under the environmentof the dynamic explicit FEM code ABAQUS/Explicit.The influencing laws of processing parameters on wrinkling in the bendingprocess are simulated and then analyzed by numerical simulation method. The resultsshow that:Use mandrel and lower support roller can improve the rectangular tube’s bendingstrength, increase the stability of the compression deformation, weakened thewrinkling trend obviously. The wrinkle deformation can’t be reduced, when thefriction coefficient between support roller and rectangular tube which should bedetermined by experiment or theoretical analysis is too large or small. The frictioncoefficient between support roller and Q235steel tube this model used is set around0.08. The bending feed rate doesn’t have a big influence on the stress distribution and wrinkling waviness. All these results are valuable reference for the technologicaldesign and the real production of thin-walled rectangular tube bending formingprocess.