Abstract
The short life and high cost of ring die restrict the development of pelletizing technology severely. To solve the problem, this paper focuses on the effect of die hole structure and distribution on the die strength by finite element analysis. At first, a parametric model with one random hole surrounded by six same holes is established. Through ANSYS Design Exploration, the significant design parameters affecting the deformation and stress of the die were clarified. Furthermore, the effects of the significant parameters on the total deformation and equivalent stress were obtained by response surface analysis. In addition, the empirical equations between deformation/stress and the significant parameters were developed and the interactions of any two parameters were investigated. The results show that the equations reach a high degree of significance and the coefficient of determination R2 is 0.9803, which means it can predict the total deformation and equivalent stress correctly. Moreover, the optimal combination of the parameters was achieved. When the smallest deformation and equivalent stress of ring die are obtained in the range of parameters value, the cone angle of die hole inlet is 14.67°, the effective diameter is 2.7mm, the radial vertical distance between two adjacent die holes is 10mm and the angle is 2.7°. Using the multi-objective optimization method based on the finite element to study the influence of design parameters on the ring die strength provides an effective method and idea for the design of ring die.