Analysis of loads on the shearing edge during electrohydraulic trimming of AHSS steel in comparison with conventional trimming

The results of the analytical study indicate that the maximum contact pressure is applied to the trimming tool at the lower endpoint of the shearing edge, but the point of maximum plastic deformation in the tool is found on the vertical wall of the shearing edge where it contacts the area of the blank where separation takes place. The shearing edge of the EH trimming die experiences less contact pressure and less plastic deformation with increase of the radius of the shearing edge. The shearing edge of the EH trim die has a tendency to dull after a number of trimming cycles. In addition, when compared with conventional trim die, the shearing edge of the EH trimming tool experiences slightly higher (10-15%) contact loads than in conventional trimming. However, plastic deformations occurring in the conventional trim die for shearing of identical material are larger. Analysis of loads on the EH trimming tool was repeated for purely elastic tool material to formulate the requirements to the material of the shearing edge.