A Variational Approach to Upper-Bound Analysis of Bimetal Rod Extrusion

• Main Authors: Chung, Wen-Der, 莊文德
• Other Authors: Wei-Chin Yeh
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/35775126626820336463

碩士 === 國立中央大學 === 機械工程學系 === 84 === The purpose of this research is to analyze bimetal rod extrusion with upper-bound method. The difference of this article from traditional ones is : During the process of minimizing the upper-bound energy,the variational approach isapplied. Besides kinematically admissible boundary condition, we can get naturalboundary conditions that traditional upper- bound method ignores. First,we assume the deforming field as generalizd boundaries of the plasticzone.From the satisfaction of kinematically admissible velocity field,we can derive upper- bound energy equation. With variational method,we can minimize energyequation to derive natural boundary condition of the core. As to the numericalupper-bound solution,ths rsearch uses the function "Findmin" of software "Mathematica". We also use it to decide the free parameters,and to calculate energy and predict the deforming behavior. Except the analysis of the effect of operation conditions on the energy and plastic deforming behavior,this article also compares with traditional upper-bound analysis.We get either lower energy consumption or the prediction of thedeforming field is more reasonable.