应用刚粘塑性有限元法对圆柱体在两平板间镦粗时的应力场进行了分析 ,给出了毛坯在不同初始高径比时的心部应力随压下量的变化曲线。由此得出 :在变形过程中 ,圆柱体心部存在两向拉应力 ;并且在墩粗过程中 ,当瞬时高径比约为 1 .0时 ,心部σθ、σr 由拉应力转变为压应力。 The application of viscoplastic finite element method to the analysis of the stress field of the cylinder upsetting between the two plates gives the curve of the stress on the core under different initial aspect ratios. It is concluded that there is biaxial tensile stress in the center of the cylinder during the deformation process, and when the instantaneous aspect ratio is about 1.0, the core σθ and σr are transformed from tensile stress to pressure stress.