The theory of slip-linefield is an effective method for problems of plane strain of perfect plastic solids, and the circle-fan field is used frequently.
滑移线理论是解刚塑性平面应变间题的一种有效方法，而圆扇形场则是常使用的。
2
The deforming force of cone-die direct extrusion is solved by a mathematic method based on the simplified flow model of sliplinefield.