凹形坯料平板镦粗应力场的有限元分析

STRESS FIELD FINITE ELEMENT ANALYSIS OF CONCAVE BLANK DURING UPSETTING OF FLAT PLATENS

应用刚粘塑性有限元法对凹形坯料在两平板间镦粗时的应力场进行了分析, 给出了毛坯在不同侧表面母线形状时的应力随压下量的变化曲线, 并通过与圆柱体平板镦粗应力场的比较得出: 在变形过程中, 凹形坯料心部也存在两向拉应力; 母线形状选取不当将导致侧表面切向应力为正;

In this paper,rigid viscoplastic finite element method is used to solve the stress field of concave blank during upsetting of two flat platens.The stress-height reduction curves of different generating line of concave blank were obtained.By comparing stress field of concave with stress field of cylinder,it conducts that:in the center of concave blank,there is two dimensional tensile stress during upsetting,and when the generating line of concave blank is made incorrectly,tangential stress σ θ of outside surface turns into tensile stress.It is also discovered that equivalent strain field of concave blank is more uniform than that of cylinder.