The Research On Deformation And Finite Element Analysis Of Large Bending Radius Tube In Process Of Push Bending

The bending forming of Large bending radius tube mainly uses push bending tocomplete plastic processing; it has such advantages as simple mold parameters, simpleprocess, and avoiding waste material. However, owing to coupled effects of multi-factorsinteraction in the push bending process, Large bending radius tube emerges the problems ofinstability and springback at the later stage of push bending, which greatly affects thebending quality of the tube. In terms of the above problems, the paper adoptsThree-dimensional finite element numerical simulation technology to do a systematicresearch about instability, springback and technological parameters in the process of thebending forming of Large bending radius tube and material parameters which effectsinstability and springback. The research has a great theoretical significance and referencevalue for the development of the bending forming of Large bending radius tube technologyand the selection and optimization of technological parameters in the forming process.The mainly research contents and results are as follows:Based on dynamic finite element (ABAQUS/Explicit) software, it establishes theactual pushing elbow model taking the calculation accuracy and the computationalefficiency of Large bending radius tube push roll forming of three dimensional finiteelement model into consideration, and analyses and solves the involved key technicalproblems of the modeling process. The models for operation and test results are comparedand analyzed, and the results coincide well. It lays a foundation for the research of processparameters and material parameters for the Large bending radius tube pushing process ofspringback and instability of the influence law analysis.Based on Large bending radius tube push bending three dimensional finite elementmodel, the paper analyzes the influence law of the process parameters and materialparameters on the push bending springback angle after unloading. The main researchincludes relative bending radius, relative wall thickness, push wheel and shell frictioncoefficient, other mold and shell friction coefficient, synchronous block boosting speed, themandrel stretch into quantity, mold and tube billet gap, Material strength coefficient,hardening exponent of some factors such as bending radius tube bending springback ofpush, and concludes the figure of rule curve.When analyzing the influence law of process parameters and material parameters to Large bending radius tube push bending instability, the paper mainly researches theinfluence law of relative wall thickness, relative bending radius, push wheel and shellfriction coefficient and material hardening exponent, strength coefficient in the fixed Anglewithin the tube billet deformation zone section wall thickness, and the law of eachrespective buckling angle with push the process of bending stress strain and thicknesschanging. At the same time, we do the research at the angle of0.75, the influence law ofsynchronous pieces of boosting speed, boosting pieces of boosting speed, mold and tubebillet gap and mold and shell friction coefficients on the tube billet deformation zonesection wall thickness and equivalent strain.According to the acquired laws of Large bending radius tube push bending，based onresponse surface methodology to optimize the influence parameters of large bending radiustube’s springback, The optimization results indicate that the optimized aluminum alloy tubeproduces the springback angle smaller than before optimization of springback angle.Therefore, the optimization method has the vital significance for improving the tube billetbending quality.