In order to reduce high calibration pressure in hydroforming of components with too small radii, a method wasproposed to manufacture automotive hollow components with rectangular shape by relatively lower pressure. Th...In order to reduce high calibration pressure in hydroforming of components with too small radii, a method wasproposed to manufacture automotive hollow components with rectangular shape by relatively lower pressure. Theprocess is simulated and analyzed. It is thought that the friction force between the die surface and tube is a mainreason that high pressure is needed to form small radii. Using the method proposed in this paper, a petal-like sectionshape is first preformed so that the central zones of the four sides of the preform section do not contact with the diesides, thus the tube metal is easy to flow into the transition radii area in calibration stage. Moreover, a positive forcealong the sides is produced by the internal pressure, which is beneficial to overcome the friction force and push thematerial into the radii. Therefore, the pressure for forming the transition radii is greatly reduced and the componentswith small radii can be formed with relatively lower pressure. For the experimental case conducted in this paper, theforming pressure is reduced by about 28.6% than the estimated forming pressure.展开更多
The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and i...The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and it was hard to make it satisfied with traditional forming process. This paper proposed a FEM model of hollow workpiece of CWR in the sizing process, and simulated the deformation condition using the ANSYS program. Three kinds of parts with different wall thickness were calculated. Some stress and strain fields of the deformed hollow parts at various conditions are gained. The influence of wall thickness on the distribution of stress and strain was analyzed. The paper also found two phenomena, which never have been seen at traditional experiment, and author tried to give some explanations. The ANSYS program provided the relationship between the tolerance of the deformed workpiece and the deforming parameter. It is helpful to design the sizing dies of a new precise forming process of hollow parts on the CWR. The new process that designed through the information of FEM improved the accuracy of hollow parts on CWR. It proved the validity and practicability of numerical simulation.展开更多
文摘In order to reduce high calibration pressure in hydroforming of components with too small radii, a method wasproposed to manufacture automotive hollow components with rectangular shape by relatively lower pressure. Theprocess is simulated and analyzed. It is thought that the friction force between the die surface and tube is a mainreason that high pressure is needed to form small radii. Using the method proposed in this paper, a petal-like sectionshape is first preformed so that the central zones of the four sides of the preform section do not contact with the diesides, thus the tube metal is easy to flow into the transition radii area in calibration stage. Moreover, a positive forcealong the sides is produced by the internal pressure, which is beneficial to overcome the friction force and push thematerial into the radii. Therefore, the pressure for forming the transition radii is greatly reduced and the componentswith small radii can be formed with relatively lower pressure. For the experimental case conducted in this paper, theforming pressure is reduced by about 28.6% than the estimated forming pressure.
文摘The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and it was hard to make it satisfied with traditional forming process. This paper proposed a FEM model of hollow workpiece of CWR in the sizing process, and simulated the deformation condition using the ANSYS program. Three kinds of parts with different wall thickness were calculated. Some stress and strain fields of the deformed hollow parts at various conditions are gained. The influence of wall thickness on the distribution of stress and strain was analyzed. The paper also found two phenomena, which never have been seen at traditional experiment, and author tried to give some explanations. The ANSYS program provided the relationship between the tolerance of the deformed workpiece and the deforming parameter. It is helpful to design the sizing dies of a new precise forming process of hollow parts on the CWR. The new process that designed through the information of FEM improved the accuracy of hollow parts on CWR. It proved the validity and practicability of numerical simulation.
