Numerical Simulation Study On Bending For Forming Axially Symmetrical Fin Tube

During the process of tube bending, internal wall thickening and wrinkling,external wall thinning and rupture, cross section distortion and the springback afterunloading are all the research scholars’ current focus all over the world. In addition tothe above-described technical problems, the bending process of axial symmetry fintube this paper studies is complex and transition zone of the flat steel and light tubepossibly appears cracking problems. For these problems, traditional experimentalmethods consume so much researching time and lead a high cost. Through thenumerical simulation on roll bending process of the axial symmetry fin tube to obtainthe reasonable process load parameters can not only make important theoreticalsignificance, but also provide important technical support for the practical production.The major research contents of this paper are as follows:(1) Establish the material model of the axial symmetry fin tube in the process ofroll bending. Obtain the basic mechanics performance parameters of the materialthrough single tensile test. Obtain the true stress-strain curve of materials through thetrue stress and true strain formula deducing, then establish the material model.(2) According to the roll forming process of the axial symmetry fin tube, establishthree-dimensional finite element model based on the ABAQUS finite elementsimulation software, and study on every module settings of finite elementpre-treatment. Acquire the method to set parameters of the finite module such aselement meshing technology, boundary conditions and contact conditions.(3) Using the established finite element model to make a numerical simulationresearch on the roll bending forming process of the axial symmetry fin tube and thecircular light tube. Analysis the equivalent stress and strain distribution rules,tangential stress and strain curve under the different bending angles. The study findsthat the axial symmetry fin tube is more obvious in the aspects of cross section distortion and inside wall wrinkling trend compared with circular light tube.(4) First establish the performance evaluation method on roll bending of the axial symmetry fin tube, And introduce to the simplify relation between the amount of press, roller center distance and the radius of the curvature. Take a derivative with dRr/dh and the amount of press to get their relations.and the maxima of the amount of press. Make the comparison of the theoretical and simulation radius of curvature and the error analysis. According to the graph of the relations between radius of curvature and the amount of press to get suitable ranges of the amount of press. According to the variation curves of ellipticity and the external wall thickness and its equivalent stress and strain.to analyze the influence of the press amount, the center distance of roller, the roller speed and friction coefficient on the quality of the fin tube forming to get their suitable ranges.