Papers by Keyword: Hourglass Control

Abstract: A single-point load will be applied on the ring in the cold ring rolling process when the ring vibrates violently. This arouses hourglass in finite element simulation of the process using reduced integration element. A one-point quadrature element with hourglass control developed by Hu is used, and the user-defined control parameters are not required. Hourglass energy can be reduced to 3 percent of the internal energy. The element is applied to simulation of a pure radial cold ring rolling with rectangular section. Compared with the experimental results, the simulation results are proved to be accurate. Key-Words: one-point quadrature; Hourglass control; finite element; cold ring rolling

Abstract: Hourglass is obviously aroused in cold ring rolling simulation with reduced integration element because of ring vibrating violently and small contact area of ring and rollers. In the developed numerical simulation code named RingForm, two methods are used to control the hourglass. The first method is combination of artificial damping and artificial stiffness. The second is one-point quadrature element with hourglass control, which need not user-defined control parameters. Hourglass energy can be reduced to 3 percent of the internal energy. Using the latter, good elements are acquired, while computational efficiency is obviously lower than the former.

Abstract: The two methods of artificial damping and artificial stiffness are developed in dynamic explicit FEA code for ring rolling. Advantages and disadvantages of artificial damping method and artificial stiffness method are analyzed. A rectangular section cold ring rolling is simulated. The hourglass energy and the ratio of the hourglass energy to the internal energy are compared between the two hourglass control methods. The hourglass control coefficient criterion of the two methods in the cold ring rolling simulation is proposed.