The Prediction of Friction Factor of The Forging Workpiece

• Main Authors: Chorng-Der Li, 李重德
• Other Authors: Cheng-I Weng
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/63609271251241459146

碩士 === 國立成功大學 === 機械工程研究所 === 84 === Owing to the effect of friction is very important for the surface of a workpiece during the metal forming. However, the most of previous researchers give a constant friction factor or use the curve of ring compression accompanying with experiment to decide the friction factor to analyze the process of the metal forming, but we can not know whether the constant friction is right or not. In addition, the major shortcoming of this method is that too many experiments must be carried out under the different operational condition. Therefore, an efficiency and new method is proposed in this paper to predict the constant friction factor between the workpiece and die. For a preliminary study the feasibility of the present method the upsetting is used to access the effect of the operational conditions on the friction factor. In direc analysis , the rigid-viscoplastic material and incompressible condition. In inverse analysis, the friction factor is predicted by using the golden section method accompanying with experiment, in which the relationship between load and displacement are obtained. The influence of the operational conditions and different materials of the workpieces on the friction factor can be verified and accessed. From the obtained results of this study, this inverse method is reliable and provide a fast way to predict the friction coefficient. Furthermore, the friction factor is smaller when the velocity of die is increased or the material of the workpiece is harder.