The invention relates to a method for calculating the dead zone morphology by using the
metal slip line theory complete theory. The method comprises the following steps: firstly, determining the
radius of a blunt circle of a tool
nose of a used tool through measurement; and then front angles and friction angles of all positions on the blunt circle of the tool
nose need to be calculated, and then shearing angles of all the positions, namely the shearing direction of
metal, are obtained. And obtaining the
friction coefficient of each position by using the
friction angle, and further solving theincluded angle between the
metal slip line and the plastic boundary, namely the included angle between the
boundary line of the dead zone and the blunt circle of the tool
nose; the metal shearing direction is collinear with the
boundary line of the dead zone, so that the positions of the vertexes S1 and S2 of the dead zone on the blunt circle of the tool nose can be solved. And after judging whether the vertexes S1 and S2 exist or not, deriving and solving the position of the vertex S3 through a geometrical relationship by utilizing the positions of the vertexes S1 and S2 and the included angle between the
boundary line of the dead zone at the two points and the blunt circle of the tool nose, so as to completely determine the morphology of the dead zone of the tool nose. According to the method, the complete morphology of the dead zone of the tool nose can be predicted through complete theoretical calculation without any factors needing to be given manually.